View source for Diarrhea

{{Short description|Loose or liquid bowel movements}}
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{{Infobox medical condition (new)
| name            = Diarrhea
| synonyms        = Diarrhoea (or diarrhœa)
| image           = Multiple rotavirus particles.jpg
| caption         = An electron micrograph of [[rotavirus]], the cause of nearly 40% of hospitalizations from diarrhea in children under five<ref name=WHO2010a/>
| field           = [[Infectious disease (medical specialty)|Infectious disease]], [[gastroenterology]]
| symptoms        = Loose frequent bowel movements, [[dehydration]]<ref name=WHO2013/>
| onset           =
| duration        =
| causes          = Usually infection (viral, bacterial, parasitic)<ref name=WHO2013/>
| risks           = Contaminated food or water<ref name=WHO2013/>
| diagnosis       =
| differential    =
| prevention      = [[Handwashing]], [[rotavirus vaccination]], [[breastfeeding]]<ref name=WHO2013/>
| treatment       = [[Oral rehydration solution]], [[zinc supplementation]]<ref name=WHO2013/>
| medication      =
| frequency       = ≈2.4 billion (2015)<ref name=GBD2015Pre>{{cite journal | vauthors = Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, etal | collaboration = GBD 2015 Disease and Injury Incidence and Prevalence Collaborators | title = Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015 | journal = Lancet | volume = 388 | issue = 10053 | pages = 1545–1602 | date = October 2016 | pmid = 27733282 | pmc = 5055577 | doi = 10.1016/S0140-6736(16)31678-6 }}</ref>
| deaths = 1.53 million (2019)<ref name = "Dadonaite_2018">{{Cite journal |vauthors=Dadonaite B, [[Hannah Ritchie|Ritchie H]], Roser M |date=2018-11-01 |title=Diarrheal diseases |url=https://ourworldindata.org/diarrheal-diseases |journal=Our World in Data |access-date=28 April 2022 |archive-date=19 June 2022 |archive-url=https://web.archive.org/web/20220619212714/https://ourworldindata.org/diarrheal-diseases |url-status=live }}</ref>
}}

<!-- FYI: The first and last paragraph of the lead are transcluded in the article on [[WASH]], see the section on health -->
'''Diarrhea''' ([[American English]]), also spelled '''diarrhoea''' or '''diarrhœa''' ([[British English]]), is the condition of having at least three loose, liquid, or watery [[defecation|bowel movement]]s in a day.<ref name=WHO2013>{{cite web|date=2 May 2017|title=Diarrhoeal disease Factsheet|url=https://www.who.int/en/news-room/fact-sheets/detail/diarrhoeal-disease|access-date=29 October 2020|website=World Health Organization|archive-date=11 November 2020|archive-url=https://web.archive.org/web/20201111202300/https://www.who.int/en/news-room/fact-sheets/detail/diarrhoeal-disease|url-status=live}}</ref> It often lasts for a few days and can result in [[dehydration]] due to fluid loss.<ref name=WHO2013/> Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour.<ref name=WHO2013/> This can progress to decreased [[urination]], [[pallor|loss of skin color]], a [[tachycardia|fast heart rate]], and a [[Altered level of consciousness|decrease in responsiveness]] as it becomes more severe.<ref name=WHO2013/> Loose but non-watery [[feces|stool]]s in babies who are exclusively [[Breastfeeding|breastfed]], however, are normal.<ref name=WHO2013/>

[[file:En.Wikipedia-VideoWiki-Diarrhea.webm|thumb|What is diarrhea? How is it caused, treated and prevented? (see also [[Wikipedia:VideoWiki/Diarrhea|script]])]]The most common cause is an infection of the [[intestine]]s due to a [[virus]], [[bacterium]], or [[parasite]]—a condition also known as [[gastroenteritis]].<ref name=WHO2013/> These infections are often acquired from food or water that has been contaminated by [[Human feces|feces]], or directly from another person who is infected.<ref name=WHO2013/> The three types of diarrhea are: short duration watery diarrhea, short duration bloody diarrhea, and persistent diarrhea (lasting more than two weeks, which can be either watery or bloody).<ref name=WHO2013/> The short duration watery diarrhea may be due to [[cholera]], although this is rare in the developed world.<ref name=WHO2013/> If blood is present, it is also known as [[dysentery]].<ref name=WHO2013/> A number of non-infectious causes can result in diarrhea.<ref name=CEM2013/> These include [[lactose intolerance]], [[irritable bowel syndrome]], [[non-celiac gluten sensitivity]], [[Coeliac disease|celiac disease]], [[inflammatory bowel disease]] such as [[ulcerative colitis]], [[hyperthyroidism]], [[bile acid diarrhea]], and a number of medications.<ref name=CEM2013>{{cite book | veditors = Abdelmalak B, Doyle J |title=Anesthesia for otolaryngologic surgery |date=2013 |publisher=Cambridge University Press |isbn=978-1-107-01867-9 |pages=282–287}}</ref><ref name=SaponeBai>{{cite journal | vauthors = Sapone A, Bai JC, Ciacci C, Dolinsek J, Green PH, Hadjivassiliou M, Kaukinen K, Rostami K, Sanders DS, Schumann M, Ullrich R, Villalta D, Volta U, Catassi C, Fasano A | title = Spectrum of gluten-related disorders: consensus on new nomenclature and classification | journal = BMC Medicine | volume = 10 | article-number = 13 | date = February 2012 | pmid = 22313950 | pmc = 3292448 | doi = 10.1186/1741-7015-10-13 | type = Review | doi-access = free }} {{open access}}</ref><ref>{{cite journal | vauthors = Slattery SA, Niaz O, Aziz Q, Ford AC, Farmer AD | title = Systematic review with meta-analysis: the prevalence of bile acid malabsorption in the irritable bowel syndrome with diarrhoea | journal = Alimentary Pharmacology & Therapeutics | volume = 42 | issue = 1 | pages = 3–11 | date = July 2015 | pmid = 25913530 | doi = 10.1111/apt.13227 | s2cid = 34603226 | url = http://eprints.whiterose.ac.uk/86190/3/MANUSCRIPT-REVISED%5B1%5D.pdf | doi-access = free | access-date = 23 September 2019 | archive-date = 9 May 2020 | archive-url = https://web.archive.org/web/20200509035023/http://eprints.whiterose.ac.uk/86190/3/MANUSCRIPT-REVISED%5B1%5D.pdf | url-status = live }}</ref> In most cases, [[Stool test|stool cultures]] to confirm the exact cause are not required.<ref name=NEJM2014/>

Diarrhea can be prevented by improved [[sanitation]], clean [[drinking water]], and [[hand washing]] with soap.<ref name=WHO2013/> [[Breastfeeding]] for at least six months and [[rotavirus vaccine|vaccination against rotavirus]] is also recommended.<ref name=WHO2013/> [[Oral rehydration therapy|Oral rehydration solution]] (ORS)—clean water with modest amounts of salts and [[sugar]]—is the treatment of choice.<ref name=WHO2013/> [[Zinc#Dietary supplement|Zinc tablets]] are also recommended.<ref name=WHO2013/> These treatments have been estimated to have saved 50&nbsp;million children in the past 25 years.<ref name=WHO2010a>{{cite web |url=http://whqlibdoc.who.int/publications/2009/9789241598415_eng.pdf |title=whqlibdoc.who.int |work=[[World Health Organization]] |url-status=live |archive-url=https://web.archive.org/web/20101108051648/http://whqlibdoc.who.int/publications/2009/9789241598415_eng.pdf |archive-date=8 November 2010 }}</ref> When people have diarrhea it is recommended that they continue to eat healthy food, and babies continue to be breastfed.<ref name=WHO2013/> If commercial ORS is not available, homemade solutions may be used.<ref name=Prober2012>{{cite book | vauthors = Crockett ME, Keystone JS | chapter = Protection of Travelers | veditors = Fischer M, Long SS, Prober CG | title=Principles and practice of pediatric infectious diseases|date=2012|publisher=Elsevier Saunders|location=Edinburgh |isbn=978-1-4557-3985-1 |page=82 |edition=4th | chapter-url= https://books.google.com/books?id=TN2Gu2Af1BIC&pg=PA82 }}</ref> In those with severe dehydration, [[Intravenous therapy|intravenous fluids]] may be required.<ref name=WHO2013/> Most cases, however, can be managed well with fluids by mouth.<ref>{{cite web|author1=ACEP|title=Nation's Emergency Physicians Announce List of Test and Procedures to Question as Part of Choosing Wisely Campaign|url=http://www.choosingwisely.org/nations-emergency-physicians-announce-list-of-test-and-procedures-to-question-as-part-of-choosing-wisely-campaign/|website=Choosing Wisely|date=14 October 2013|access-date=18 June 2014|url-status=live|archive-url=https://web.archive.org/web/20140517042652/http://www.choosingwisely.org/nations-emergency-physicians-announce-list-of-test-and-procedures-to-question-as-part-of-choosing-wisely-campaign/|archive-date=17 May 2014}}</ref> [[Antibiotic]]s, while rarely used, may be recommended in a few cases such as those who have bloody diarrhea and a high fever, those with severe [[travelers diarrhea|diarrhea following travelling]], and those who grow specific bacteria or parasites in their stool.<ref name=NEJM2014/> [[Loperamide]] may help decrease the number of bowel movements but is not recommended in those with severe disease.<ref name=NEJM2014>{{cite journal | vauthors = DuPont HL | title = Acute infectious diarrhea in immunocompetent adults | journal = The New England Journal of Medicine | volume = 370 | issue = 16 | pages = 1532–40 | date = April 2014 | pmid = 24738670 | doi = 10.1056/nejmra1301069 }}</ref>

About 1.7 to 5&nbsp;billion cases of diarrhea occur per year.<ref name=WHO2013/><ref name=CEM2013/><ref name=GBD2013>{{cite journal | vauthors = Vos T, Barber RM, Bell B, Bertozzi-Villa A, Biryukov S, Bolliger I | collaboration = Global Burden of Disease Study 2013 Collaborators | title = Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013 | journal = Lancet | volume = 386 | issue = 9995 | pages = 743–800 | date = August 2015 | pmid = 26063472 | pmc = 4561509 | doi = 10.1016/s0140-6736(15)60692-4 }}</ref> It is most common in [[developing countries]], where young children get diarrhea on average three times a year.<ref name=WHO2013/> Total deaths from diarrhea are estimated at 1.53&nbsp;million in 2019—down from 2.9 million in 1990.<ref name = "Dadonaite_2018" /> In 2012, it was the second most common cause of [[Infant mortality|deaths in children]] younger than five (0.76 million or 11%).<ref name=WHO2013/><ref name=CDC2013/> Frequent episodes of diarrhea are also a common cause of [[malnutrition]] and the most common cause in those younger than five years of age.<ref name="WHO2013"/> Other long term problems that can result include [[stunted growth]] and poor intellectual development.<ref name=CDC2013>{{cite web|title=Global Diarrhea Burden|url=https://www.cdc.gov/healthywater/global/diarrhea-burden.html|website=CDC|access-date=18 June 2014|date=24 January 2013|url-status=live|archive-url=https://web.archive.org/web/20140707153625/http://www.cdc.gov/healthywater/global/diarrhea-burden.html|archive-date=7 July 2014}}</ref>

== Terminology ==

The word diarrhea is from the [[Ancient Greek]] {{lang|grc|[[wikt:διάρροια|διάρροια]]}} from {{lang|grc|διά}} ''{{lang|grc-Latn|dia}}'' "through" and {{lang|grc|ῥέω}} ''{{lang|grc-Latn|rheo}}'' "flow".

''Diarrhea'' is the spelling in [[American English]], whereas ''diarrhoea'' is the spelling in [[British English]]. [[Canadian English]] uses both spellings.

Slang terms for the condition include "the runs", "the squirts" (or "squits" in Britain<ref>{{Wiktionary-inline|squits}}</ref>), "[[The Hershey Company|Hershey]] squirts", "[[Moctezuma II|Montezuma]]'s Revenge", and "the trots".<ref>{{Wiktionary-inline|runs}}</ref><ref>{{cite dictionary|url=https://www.merriam-webster.com/dictionary/diarrhea#synonyms|dictionary=[[Merriam Webster]]|title=Definition of Diarrhea by Merriam-Webster|access-date=11 December 2018|archive-date=11 December 2018|archive-url=https://web.archive.org/web/20181211052241/https://www.merriam-webster.com/dictionary/diarrhea#synonyms|url-status=live}}</ref>
 
The word is often pronounced as {{IPAc-en|ˌ|d|aɪ|ə|ˈ|r|i:|ə}} {{respell|DY|ə|REE|ə}}.

== Definition ==
[[file:BristolStoolChart.png|[[Bristol stool scale]]|thumb]]

Diarrhea is defined by the [[World Health Organization]] as having three or more loose or liquid [[Defecation|stools]] per day, or as having more stools than is normal for that person.<ref name=WHO2013/>

Acute diarrhea is defined as an abnormally frequent discharge of semisolid or fluid fecal matter from the bowel, lasting less than 14 days, by [[World Gastroenterology Organisation|World Gastroenterology Organization]].<ref name="WGO">{{cite web |url=http://www.worldgastroenterology.org/acute-diarrhea-in-adults.html |title=WGO Practice Guideline – Acute diarrhea |access-date=9 March 2011 |url-status=live |archive-url=https://web.archive.org/web/20110222012123/http://www.worldgastroenterology.org/acute-diarrhea-in-adults.html |archive-date=22 February 2011 }}</ref> Acute diarrhea that is watery may be known as AWD (Acute Watery Diarrhoea.)<ref>{{cite web |title=Cholera outbreak toobox |url=https://www.who.int/docs/default-source/outbreak-toolkit/cholera-outbreak-data-collection-toolbox---layout-inis-27-june.pdf?sfvrsn=60036811_2 |publisher=WHO |access-date=2 May 2022 |date=June 2019 |archive-date=30 May 2022 |archive-url=https://web.archive.org/web/20220530170149/https://www.who.int/docs/default-source/outbreak-toolkit/cholera-outbreak-data-collection-toolbox---layout-inis-27-june.pdf?sfvrsn=60036811_2 |url-status=live }}</ref>

===Secretory===
Secretory diarrhea means that there is an increase in the active secretion, or there is an inhibition of absorption. There is little to no structural damage. The most common cause of this type of diarrhea is a [[cholera toxin]] that stimulates the secretion of [[anion]]s, especially [[chloride]] ions (Cl<sup>–</sup>). Therefore, to maintain a charge balance in the [[gastrointestinal tract]], sodium (Na<sup>+</sup>) is carried with it, along with water. In this type of diarrhea intestinal fluid secretion is [[Tonicity#3|isotonic]] with plasma even during fasting.<ref name="webmd.com">{{cite web |url=http://www.webmd.com/digestive-disorders/digestive-diseases-diarrhea |title=The Basics of Diarrhea |publisher=Webmd.com |date=17 February 2011 |access-date=9 March 2011 |url-status=live |archive-url=https://web.archive.org/web/20110311010926/http://www.webmd.com/digestive-disorders/digestive-diseases-diarrhea |archive-date=11 March 2011 }}</ref><ref name="MoonZhang2015"/> It continues even when there is no oral food intake.

===Osmotic===
Osmotic diarrhea occurs when too much water is drawn into the bowels. If a person drinks solutions with excessive sugar or excessive salt, these can draw water from the body into the bowel and cause osmotic diarrhea.<ref name=WHOtreatmentdiarrhoea2005>{{cite web|url = http://whqlibdoc.who.int/publications/2005/9241593180.pdf|title = The Treatment Of Diarrhea, A manual for physicians and other senior health workers|publisher = [[World Health Organization]]|version = Sometimes needs to be downloaded twice. See "4.2 Treatment Plan A: home therapy to prevent dehydration and malnutrition", "4.3 Treatment Plan B: oral rehydration therapy for children with some dehydration", and "4.4 Treatment Plan C: for patients with severe dehydration" on pages 8 to 16 (12–20 in PDF). See also "8. Management of Diarrhoea with Severe Malnutrition" on pages 22–24 (26–30 in PDF) and "Annex 2: Oral and Intravenous Rehydration Solutions" on pages 33–37 (37–41 in PDF).|year = 2005|archive-url = https://web.archive.org/web/20111019172153/http://whqlibdoc.who.int/publications/2005/9241593180.pdf|archive-date = 19 October 2011}}</ref><ref name="MoonZhang2015"/> Osmotic diarrhea can also result from maldigestion (e.g., pancreatic disease or [[coeliac disease]]) in which the nutrients are left in the [[Lumen (anatomy)|lumen]] to pull in water. Or it can be caused by osmotic [[laxatives]] (which work to alleviate [[constipation]] by drawing water into the bowels). In healthy individuals, too much [[magnesium]], [[vitamin C|vitamin&nbsp;C]] or undigested [[lactose]] can produce osmotic diarrhea and distention of the bowel. A person who has [[lactose intolerance]] can have difficulty absorbing lactose after an extraordinarily high intake of dairy products. In persons who have [[fructose malabsorption]], excess fructose intake can also cause diarrhea. High-fructose foods that also have a high glucose content are more absorbable and less likely to cause diarrhea. [[Sugar alcohol]]s such as [[sorbitol]] (often found in sugar-free foods) are difficult for the body to absorb and, in large amounts, may lead to osmotic diarrhea.<ref name="webmd.com"/> In most of these cases, osmotic diarrhea stops when the offending agent (e.g., milk or sorbitol) is stopped.

===Exudative===
Exudative diarrhea occurs with the presence of blood and pus in the stool. This occurs with [[inflammatory bowel diseases]], such as [[Crohn's disease]] or [[ulcerative colitis]], and other severe infections such as ''[[Escherichia coli|E.&nbsp;coli]]'' or other forms of food poisoning.<ref name="MoonZhang2015"/><ref name="webmd.com"/>

===Inflammatory===
Inflammatory diarrhea occurs when there is damage to the mucosal lining or brush border, which leads to a passive loss of protein-rich fluids and a decreased ability to absorb these lost fluids. Features of all three of the other types of diarrhea can be found in this type of diarrhea.<ref>{{cite journal | vauthors = Sweetser S | title = Evaluating the patient with diarrhea: a case-based approach |doi-access=free | journal = Mayo Clinic Proceedings | volume = 87 | issue = 6 | pages = 596–602 | date = June 2012 | pmid = 22677080 | pmc = 3538472 | doi = 10.1016/j.mayocp.2012.02.015 }}</ref> It can be caused by bacterial infections, viral infections, parasitic infections, or autoimmune problems such as inflammatory bowel diseases. It can also be caused by tuberculosis, colon cancer, and enteritis.<ref name="MoonZhang2015"/>

===Dysentery===
If there is blood visible in the stools, it is also known as [[dysentery]]. The blood is a trace of an invasion of bowel tissue. Dysentery is a symptom of, among others, ''[[Shigella]]'', ''[[Entamoeba histolytica]]'', and ''[[Salmonella]]''.<ref name="MoonZhang2015"/>

==Health effects==

Diarrheal disease may have a negative impact on both physical fitness and mental development. "Early childhood malnutrition resulting from any cause reduces physical fitness and work productivity in adults",<ref name='d'>{{cite web | author = Disease Control Priorities Project |title=Public Health Significance of Diarrheal Illnesses |url= http://www.dcp2.org/pubs/DCP/19/Section/2531 |publisher=The World Bank Group |access-date=12 October 2013 |archive-url=https://web.archive.org/web/20140125100705/http://www.dcp2.org/pubs/DCP/19/Section/2531 |archive-date=25 January 2014 }}</ref> and diarrhea is a primary cause of childhood malnutrition.<ref>{{cite journal | vauthors = Guerrant RL, Schorling JB, McAuliffe JF, de Souza MA | title = Diarrhea as a cause and an effect of malnutrition: diarrhea prevents catch-up growth and malnutrition increases diarrhea frequency and duration | journal = The American Journal of Tropical Medicine and Hygiene | volume = 47 | issue = 1 Pt 2 | pages = 28–35 | date = July 1992 | pmid = 1632474 | doi = 10.4269/ajtmh.1992.47.28 }}</ref> Further, evidence suggests that diarrheal disease has significant impacts on mental development and health; it has been shown that, even when controlling for [[helminth]] infection and early breastfeeding, children who had experienced severe diarrhea had significantly lower scores on a series of tests of intelligence.<ref name='d' /><ref>{{cite journal | vauthors = Grantham-McGregor SM, Walker SP, Chang S | title = Nutritional deficiencies and later behavioural development | journal = The Proceedings of the Nutrition Society | volume = 59 | issue = 1 | pages = 47–54 | date = February 2000 | pmid = 10828173 | doi = 10.1017/S0029665100000069 | doi-access = free }}</ref>

Diarrhea can cause [[electrolyte imbalance]]s, [[renal impairment|kidney impairment]], [[dehydration]], and defective [[immune system]] responses. When oral drugs are administered, the efficiency of the drug is to produce a [[therapeutic effect]] and the lack of this effect may be due to the medication travelling too quickly through the digestive system, limiting the time that it can be absorbed. Clinicians try to treat the diarrheas by reducing the dosage of medication, changing the dosing schedule, discontinuation of the drug, and rehydration. The interventions to control the diarrhea are not often effective. Diarrhea can have a profound effect on the quality of life because fecal incontinence is one of the leading factors for placing older adults in [[long term care facilities]] (nursing homes).<ref name="MoonZhang2015"/>
{{clear}}

==Causes==
[[File:Stomach colon rectum diagram-en.svg|right|thumb|Diagram of the [[human gastrointestinal tract]]]]

In the latter stages of human digestion, ingested materials are inundated with water and digestive fluids such as [[gastric acid]], [[bile]], and [[digestive enzyme]]s in order to break them down into their nutrient components, which are then absorbed into the bloodstream via the [[Intestinal epithelium|intestinal tract]] in the small intestine. Prior to defecation, the large intestine reabsorbs the water and other digestive solvents in the waste product in order to maintain proper hydration and overall equilibrium.<ref>{{cite book| vauthors = Maton A, Hopkins J, McLaughlin CM, Johnson S, Warner MQ, LaHart D, Wright JD | title = Human Biology and Health| publisher = Prentice Hall| year = 1993| location = Englewood Cliffs, NJ| isbn = 978-0-13-981176-0| oclc = 32308337| url-access = registration| url = https://archive.org/details/humanbiologyheal00scho}}</ref> Diarrhea occurs when the large intestine is prevented, for any number of reasons, from sufficiently absorbing the water or other digestive fluids from fecal matter, resulting in a liquid, or "loose", bowel movement.<ref>{{Cite web |title=Diarrhea: Types, Causes, Complications & Treatment |url=https://my.clevelandclinic.org/health/diseases/4108-diarrhea |access-date=2022-07-19 |website=Cleveland Clinic |archive-date=19 July 2022 |archive-url=https://web.archive.org/web/20220719133818/https://my.clevelandclinic.org/health/diseases/4108-diarrhea |url-status=live }}</ref>

[[acute (medicine)|Acute]] diarrhea is most commonly due to viral [[gastroenteritis]] with [[rotavirus]], which accounts for 40% of cases in children under five.<ref name=WHO2010a/> In [[traveler's diarrhea|travelers]], however, [[bacterial infections]] predominate.<ref name="pmid16267716"/> Various toxins such as [[Amanita phalloides#Signs and symptoms|mushroom poisoning]] and drugs can also cause acute diarrhea.

Chronic diarrhea can be the part of the presentations of a number of chronic medical conditions affecting the intestine. Common causes include [[ulcerative colitis]], [[Crohn's disease]], [[microscopic colitis]], [[celiac disease]], [[irritable bowel syndrome]], and [[bile acid malabsorption]].<ref>{{Cite web |title=Microscopic colitis - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/microscopic-colitis/symptoms-causes/syc-20351478 |access-date=2022-07-19 |website=Mayo Clinic |language=en |archive-date=3 April 2022 |archive-url=https://web.archive.org/web/20220403123231/https://www.mayoclinic.org/diseases-conditions/microscopic-colitis/symptoms-causes/syc-20351478 |url-status=live }}</ref>

===Infections===
{{Main|Infectious diarrhea}}

There are many causes of infectious diarrhea, which include [[virus]]es, [[bacteria]] and parasites.<ref name="pmid18813221">{{cite journal | vauthors = Navaneethan U, Giannella RA | s2cid = 34096072 | title = Mechanisms of infectious diarrhea | journal = Nature Clinical Practice. Gastroenterology & Hepatology | volume = 5 | issue = 11 | pages = 637–47 | date = November 2008 | pmid = 18813221 | doi = 10.1038/ncpgasthep1264 }}</ref> Infectious diarrhea is frequently referred to as [[gastroenteritis]].<ref name=Dav2008>{{cite book|vauthors=Schlossberg D|title=Clinical Infectious Disease|date=2008|publisher=Cambridge University Press|isbn=978-1-139-57665-9|page=349|url=https://books.google.com/books?id=-wWY1_mSeq0C&pg=PA349|access-date=9 September 2017|archive-date=14 January 2023|archive-url=https://web.archive.org/web/20230114192338/https://books.google.com/books?id=-wWY1_mSeq0C&pg=PA349|url-status=live}}</ref> [[Norovirus]] is the most common cause of viral diarrhea in adults,<ref name="pmid19084472">{{cite journal | vauthors = Patel MM, Hall AJ, Vinjé J, Parashar UD | title = Noroviruses: a comprehensive review | journal = Journal of Clinical Virology | volume = 44 | issue = 1 | pages = 1–8 | date = January 2009 | pmid = 19084472 | doi = 10.1016/j.jcv.2008.10.009 }}</ref> but [[rotavirus]] is the most common cause in children under five years old.<ref name="pmid19457420">{{cite journal | vauthors = Greenberg HB, Estes MK | title = Rotaviruses: from pathogenesis to vaccination | journal = Gastroenterology | volume = 136 | issue = 6 | pages = 1939–51 | date = May 2009 | pmid = 19457420 | pmc = 3690811 | doi = 10.1053/j.gastro.2009.02.076 }}</ref> [[Adenovirus]] types 40 and 41,<ref name="pmid1962727">{{cite journal | vauthors = Uhnoo I, Svensson L, Wadell G | title = Enteric adenoviruses | journal = Baillière's Clinical Gastroenterology | volume = 4 | issue = 3 | pages = 627–42 | date = September 1990 | pmid = 1962727 | doi = 10.1016/0950-3528(90)90053-J }}</ref> and [[astrovirus]]es cause a significant number of infections.<ref name="pmid12442031">{{cite journal | vauthors = Mitchell DK | title = Astrovirus gastroenteritis | journal = The Pediatric Infectious Disease Journal | volume = 21 | issue = 11 | pages = 1067–9 | date = November 2002 | pmid = 12442031 | doi = 10.1097/00006454-200211000-00018 | s2cid = 3177998 }}</ref> [[Shiga-toxin producing Escherichia coli|Shiga-toxin producing ''Escherichia coli'']], such as [[E coli o157:h7|''E.&nbsp;coli'' o157:h7]], are the most common cause of infectious bloody diarrhea in the United States.<ref>{{Citation |last1=Akhondi |first1=Hossein |title=Bacterial Diarrhea |date=2022 |url=https://www.ncbi.nlm.nih.gov/books/NBK551643/ |work=StatPearls |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=31869107 |access-date=2022-07-19 |last2=Simonsen |first2=Kari A. |archive-date=15 June 2022 |archive-url=https://web.archive.org/web/20220615215551/https://www.ncbi.nlm.nih.gov/books/NBK551643/ |url-status=live }}</ref>

''[[Campylobacter]]'' [[species|spp.]] are a common cause of bacterial diarrhea, but infections by ''[[Salmonella]]'' spp., ''[[Shigella]]'' spp. and some strains of ''Escherichia coli'' are also a frequent cause.<ref name="pmid19116615">{{cite journal | vauthors = Viswanathan VK, Hodges K, Hecht G | title = Enteric infection meets intestinal function: how bacterial pathogens cause diarrhoea | journal = Nature Reviews. Microbiology | volume = 7 | issue = 2 | pages = 110–9 | date = February 2009 | pmid = 19116615 | pmc = 3326399 | doi = 10.1038/nrmicro2053 }}</ref>

In the elderly, particularly those who have been treated with antibiotics for unrelated infections, a toxin produced by ''[[Clostridioides difficile (bacteria)|Clostridioides difficile]]'' often causes severe diarrhea.<ref name="pmid19528959">{{cite journal | vauthors = Rupnik M, Wilcox MH, Gerding DN | s2cid = 23376891 | title = Clostridium difficile infection: new developments in epidemiology and pathogenesis | journal = Nature Reviews. Microbiology | volume = 7 | issue = 7 | pages = 526–36 | date = July 2009 | pmid = 19528959 | doi = 10.1038/nrmicro2164 }}</ref>

Parasites, particularly [[protozoa]] e.g., ''[[Cryptosporidium]]'' spp., ''[[Giardia]]'' spp., ''[[Entamoeba histolytica]]'', ''[[Blastocystis]]'' spp., ''[[Cyclospora cayetanensis]]'', are frequently the cause of diarrhea that involves chronic infection. The broad-spectrum antiparasitic agent [[nitazoxanide]] has shown efficacy against many diarrhea-causing parasites.<ref name="pmid22301075">{{cite journal | vauthors = Rossignol JF, Lopez-Chegne N, Julcamoro LM, Carrion ME, Bardin MC | title = Nitazoxanide for the empiric treatment of pediatric infectious diarrhea | journal = Transactions of the Royal Society of Tropical Medicine and Hygiene | volume = 106 | issue = 3 | pages = 167–73 | date = March 2012 | pmid = 22301075 | doi = 10.1016/j.trstmh.2011.11.007 }}</ref>

Other infectious agents, such as [[parasites]] or [[bacteria]]l toxins, may exacerbate symptoms.<ref name="pmid16267716">{{cite journal | vauthors = Wilson ME | title = Diarrhea in nontravelers: risk and etiology | journal = Clinical Infectious Diseases | volume = 41 | issue = Suppl 8 | pages = S541-6 | date = December 2005 | pmid = 16267716 | doi = 10.1086/432949 | series = 41 | doi-access = free }}</ref> In sanitary living conditions where there is ample food and a supply of clean water, an otherwise healthy person usually recovers from viral infections in a few days. However, for ill or [[malnourished]] individuals, diarrhea can lead to severe [[dehydration]] and can become life-threatening.<ref name="pmid12608880">{{cite journal | vauthors = Alam NH, Ashraf H | s2cid = 26076784 | title = Treatment of infectious diarrhea in children | journal = Paediatric Drugs | volume = 5 | issue = 3 | pages = 151–65 | year = 2003 | pmid = 12608880 | doi = 10.2165/00128072-200305030-00002 | doi-access = free }}</ref>

====Sanitation====
[[File:Slum and dirty river.jpg|thumb|Poverty often leads to unhygienic living conditions, as in this community in the Indian Himalayas. Such conditions promote contraction of diarrheal diseases, as a result of poor [[sanitation]] and [[hygiene]].]]
[[Open defecation]] is a leading cause of infectious diarrhea leading to death.<ref>{{cite web |url=https://www.who.int/mediacentre/factsheets/fs330/en/ |title=WHO &#124; Diarrhoeal disease |publisher=Who.int |access-date=10 March 2014 |url-status=live |archive-url=https://web.archive.org/web/20140401193648/http://www.who.int/mediacentre/factsheets/fs330/en/ |archive-date=1 April 2014 }}</ref>

Poverty is a good indicator of the rate of infectious diarrhea in a population. This association does not stem from poverty itself, but rather from the conditions under which impoverished people live. The absence of certain resources compromises the ability of the poor to defend themselves against infectious diarrhea. "Poverty is associated with poor housing, crowding, dirt floors, lack of access to clean water or to sanitary disposal of fecal waste ([[sanitation]]), cohabitation with domestic animals that may carry human pathogens, and a lack of refrigerated storage for food, all of which increase the frequency of diarrhea{{nbsp}}... Poverty also restricts the ability to provide age-appropriate, nutritionally balanced diets or to modify diets when diarrhea develops so as to mitigate and repair nutrient losses. The impact is exacerbated by the lack of adequate, available, and affordable medical care."<ref>{{cite book| vauthors = Jamison DT |title=Disease control priorities in developing countries|date=2006|publisher=Oxford Univ. Press|location=New York|isbn=978-0-8213-6179-5 |edition=2nd}}</ref>

One of the most common causes of infectious diarrhea is a lack of clean water. Often, improper fecal disposal leads to contamination of groundwater. This can lead to widespread infection among a population, especially in the absence of water filtration or purification. Human feces contains a variety of potentially harmful human [[pathogens]].<ref name="Brown 629–34">{{cite journal | vauthors = Brown J, Cairncross S, Ensink JH | title = Water, sanitation, hygiene and enteric infections in children | journal = Archives of Disease in Childhood | volume = 98 | issue = 8 | pages = 629–34 | date = August 2013 | pmid = 23761692 | pmc = 3717778 | doi = 10.1136/archdischild-2011-301528 }}</ref>

====Nutrition====
Proper nutrition is important for health and functioning, including the prevention of infectious diarrhea. It is especially important to young children who do not have a fully developed immune system. [[Zinc deficiency]], a condition often found in children in [[developing countries]] can, even in mild cases, have a significant impact on the development and proper functioning of the human immune system.<ref>{{cite journal|vauthors=Black RE, Sazawal S|title=Zinc and childhood infectious disease morbidity and mortality|journal=The British Journal of Nutrition|volume=85|pages=S125-9|date=May 2001|issue=Suppl 2|pmid=11509100|doi=10.1079/bjn2000304|doi-access=free}}</ref><ref>{{cite journal|vauthors=Shankar AH, Prasad AS|title=Zinc and immune function: the biological basis of altered resistance to infection|journal=The American Journal of Clinical Nutrition|volume=68|issue=2 Suppl|pages=447S–463S|date=August 1998|pmid=9701160|doi=10.1093/ajcn/68.2.447S|doi-access=free}}</ref> Indeed, this relationship between zinc deficiency and reduced immune functioning corresponds with an increased severity of infectious diarrhea. Children who have lowered levels of zinc have a greater number of instances of diarrhea, severe diarrhea, and diarrhea associated with fever.<ref>{{cite journal|vauthors=Bahl R, Bhandari N, Hambidge KM, Bhan MK|title=Plasma zinc as a predictor of diarrheal and respiratory morbidity in children in an urban slum setting|journal=The American Journal of Clinical Nutrition|volume=68|issue=2 Suppl|pages=414S–417S|date=August 1998|pmid=9701154|doi=10.1093/ajcn/68.2.414S|doi-access=free}}</ref> Similarly, [[vitamin A deficiency]] can cause an increase in the severity of diarrheal episodes. However, there is some discrepancy when it comes to the impact of vitamin A deficiency on the rate of disease. While some argue that a relationship does not exist between the rate of disease and vitamin A status,<ref>{{cite book|vauthors=Rice AL, West KP, Black RE|chapter=Vitamin A deficiency|veditors=Ezzati M, Lopez AD, Rodgers A, Murray CJ|title=Comparative quantification of health risks: global and regional burden of disease attributes to selected major risk factors.|location=Geneva|publisher=World Health Organization|year=2004|volume=1|pages=211–56, especially 238–240|chapter-url=http://apps.who.int/iris/bitstream/handle/10665/42792/9241580348_eng_Volume1.pdf|access-date=30 December 2018|archive-date=31 July 2020|archive-url=https://web.archive.org/web/20200731084243/https://apps.who.int/iris/bitstream/handle/10665/42792/9241580348_eng_Volume1.pdf|url-status=live}}</ref> others suggest an increase in the rate associated with deficiency.<ref>{{cite journal|vauthors=Sommer A, Katz J, Tarwotjo I|title=Increased risk of respiratory disease and diarrhea in children with preexisting mild vitamin A deficiency|journal=The American Journal of Clinical Nutrition|volume=40|issue=5|pages=1090–5|date=November 1984|pmid=6496388|doi=10.1093/ajcn/40.5.1090|doi-access=free}}</ref> Given that estimates suggest 127&nbsp;million preschool children worldwide are vitamin A deficient, this population has the potential for increased risk of disease contraction.<ref>{{cite journal|vauthors=West KP|title=Extent of vitamin A deficiency among preschool children and women of reproductive age|journal=The Journal of Nutrition|volume=132|issue=9 Suppl|pages=2857S–2866S|date=September 2002|pmid=12221262|doi=10.1093/jn/132.9.2857S|doi-access=free}}</ref>

===Malabsorption===
{{Main|Malabsorption}}
[[Malabsorption]] is the inability to absorb food fully, mostly from disorders in the small bowel, but also due to maldigestion from diseases of the [[pancreas]].

Causes include:{{citation needed|date=June 2021}}
* ''enzyme deficiencies or mucosal abnormality'', as in [[food allergy]] and [[food intolerance]], e.g. [[celiac disease]] (gluten intolerance), [[lactose intolerance]] (intolerance to milk sugar, common in non-Europeans), and [[fructose malabsorption]].
* ''[[pernicious anemia]]'', or impaired bowel function due to the inability to absorb [[vitamin B12|vitamin B<sub>12</sub>]],
* ''loss of pancreatic secretions'', which may be due to [[cystic fibrosis]] or [[pancreatitis]],
* ''structural defects'', like [[short bowel syndrome]] (surgically removed bowel) and radiation fibrosis, such as usually follows cancer treatment and other drugs, including agents used in [[chemotherapy]]; and
* ''certain drugs'', like [[orlistat]], which inhibits the absorption of fat.

===Inflammatory bowel disease===
{{Main|Inflammatory bowel disease}}
The two overlapping types here are of unknown origin:
* [[Ulcerative colitis]] is marked by chronic bloody diarrhea and inflammation mostly affects the distal [[colon (anatomy)|colon]] near the [[rectum]].
* [[Crohn's disease]] typically affects fairly well demarcated segments of bowel in the colon and often affects the end of the small bowel.

===Irritable bowel syndrome===
{{Main|Irritable bowel syndrome}}
Another possible cause of diarrhea is irritable bowel syndrome (IBS), which usually presents with abdominal discomfort relieved by [[defecation]] and unusual [[Human feces|stool]] (diarrhea or [[constipation]]) for at least three days a week over the previous three months.<ref>{{cite journal | vauthors = Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC | title = Functional bowel disorders | journal = Gastroenterology | volume = 130 | issue = 5 | pages = 1480–91 | date = April 2006 | pmid = 16678561 | doi = 10.1053/j.gastro.2005.11.061 }}</ref> Symptoms of diarrhea-predominant IBS can be managed through a combination of dietary changes, soluble fiber supplements and medications such as [[loperamide]] or [[codeine]]. About 30% of patients with diarrhea-predominant IBS have [[bile acid malabsorption]] diagnosed with an abnormal [[SeHCAT]] test.<ref>{{cite journal | vauthors = Wedlake L, A'Hern R, Russell D, Thomas K, Walters JR, Andreyev HJ | title = Systematic review: the prevalence of idiopathic bile acid malabsorption as diagnosed by SeHCAT scanning in patients with diarrhoea-predominant irritable bowel syndrome | journal = Alimentary Pharmacology & Therapeutics | volume = 30 | issue = 7 | pages = 707–17 | date = October 2009 | pmid = 19570102 | doi = 10.1111/j.1365-2036.2009.04081.x | s2cid = 11327665 | doi-access = free }}</ref>

===Other diseases===
Diarrhea can be caused by other diseases and conditions, namely:
* Chronic [[ethanol]] ingestion<ref name="Harrison">{{cite book | vauthors = Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL | title = Harrison's Principles of Internal Medicine | location = New York | publisher = McGraw-Hill | date = 2005 | isbn = 978-0-07-139140-5 | title-link = Harrison's Principles of Internal Medicine }}</ref>
* [[Hyperthyroidism]]<ref name="pmid26576135">{{cite journal | vauthors = Lee KJ | title = Pharmacologic Agents for Chronic Diarrhea | journal = Intestinal Research | volume = 13 | issue = 4 | pages = 306–12 | date = October 2015 | pmid = 26576135 | pmc = 4641856 | doi = 10.5217/ir.2015.13.4.306 }}</ref>
* Certain medications<ref name="pmid26576135"/>
* [[Bile acid malabsorption]]<ref name="pmid26576135"/>
* [[Ischemia|Ischemic]] bowel disease: This usually affects older people and can be due to blocked arteries.
* [[Microscopic colitis]], a type of [[inflammatory bowel disease]] where changes are seen only on histological examination of colonic biopsies.
* [[Bile salt malabsorption]] ([[primary bile acid diarrhea]]) where excessive [[bile acids]] in the [[Colon (anatomy)|colon]] produce a secretory diarrhea.
* Hormone-secreting tumors: some hormones, e.g. [[serotonin]], can cause diarrhea if secreted in excess (usually from a tumor).
* Chronic mild diarrhea in infants and toddlers may occur with no obvious cause and with no other ill effects; this condition is called [[toddler's diarrhea]].
* [[Environmental enteropathy]]
* [[Radiation enteropathy]] following treatment for pelvic and abdominal cancers.
* [[Mast cell activation syndrome]] (MCAS)<ref>{{Cite journal |last1=Afrin |first1=Lawrence B. |last2=Self |first2=Sally |last3=Menk |first3=Jeremiah |last4=Lazarchick |first4=John |date=2016-12-16 |title=Characterization of Mast Cell Activation Syndrome |journal=The American Journal of the Medical Sciences |language=en |volume=353 |issue=3 |pages=207–215 |doi=10.1016/j.amjms.2016.12.013 |pmid=28262205 |pmc=5341697 }}</ref><ref>{{Cite journal |last1=Molderings |first1=Gerhard J. |last2=Haenisch |first2=Britta |last3=Brettner |first3=Stefan |last4=Homann |first4=Jürgen |last5=Menzen |first5=Markus |last6=Dumoulin |first6=Franz Ludwig |last7=Panse |first7=Jens |last8=Butterfield |first8=Joseph |last9=Afrin |first9=Lawrence B. |date=2016 |title=Pharmacological treatment options for mast cell activation disease |journal=Naunyn-Schmiedeberg's Archives of Pharmacology |language=en |volume=389 |issue=7 |pages=671–694 |doi=10.1007/s00210-016-1247-1 |pmid=27132234 |pmc=4903110 }}</ref><ref>{{Cite journal |last1=Valent |first1=Peter |last2=Akin |first2=Cem |last3=Nedoszytko |first3=Boguslaw |last4=Bonadonna |first4=Patrizia |last5=Hartmann |first5=Karin |last6=Niedoszytko |first6=Marek |last7=Brockow |first7=Knut |last8=Siebenhaar |first8=Frank |last9=Triggiani |first9=Massimo |last10=Arock |first10=Michel |last11=Romantowski |first11=Jan |last12=Górska |first12=Aleksandra |last13=Schwartz |first13=Lawrence B. |last14=Metcalfe |first14=Dean D. |date=2020-11-27 |title=Diagnosis, Classification and Management of Mast Cell Activation Syndromes (MCAS) in the Era of Personalized Medicine |journal=International Journal of Molecular Sciences |language=en |volume=21 |issue=23 |page=9030 |doi=10.3390/ijms21239030 |doi-access=free |pmid=33261124 |pmc=7731385 }}</ref>

===Medications===
Over 700 medications, such as [[side effects of penicillin|penicillin]], are known to cause diarrhea.<ref>{{cite book | vauthors = Vallerand A | title = Davis's drug guide for nurses | publisher = F.A. Davis Company | location = Philadelphia | year = 2017 | isbn = 978-0-8036-5705-2 |pages=989–994}}</ref><ref>{{cite web | vauthors = Dekel R, Sperber AD |url=https://www.iffgd.org/lower-gi-disorders/diarrhea/diarrhea-incontinence-caused-by-medication.html |title=Diarrhea & Incontinence Caused by Medication | publisher = International Foundation for Gastrointestinal Disorders (IFFGD) |access-date=18 May 2017 |url-status=live |archive-url=https://web.archive.org/web/20170224195533/https://www.iffgd.org/lower-gi-disorders/diarrhea/diarrhea-incontinence-caused-by-medication.html |archive-date=24 February 2017 }}</ref> The classes of medications that are known to cause diarrhea are laxatives, antacids, heartburn medications, antibiotics, anti-neoplastic drugs, anti-inflammatories as well as many dietary supplements.<ref name="MoonZhang2015">{{cite journal | vauthors = Moon C, Zhang W, Sundaram N, Yarlagadda S, Reddy VS, Arora K, Helmrath MA, Naren AP | title = Drug-induced secretory diarrhea: A role for CFTR | journal = Pharmacological Research | volume = 102 | pages = 107–112 | date = December 2015 | pmid = 26429773 | pmc = 4684461 | doi = 10.1016/j.phrs.2015.08.024 }}</ref>

==Pathophysiology==
{| class="wikitable" style = "float: right; margin-left:15px; text-align:center"
|+ Ion transporters targeted by enteric infections <ref>{{cite journal | vauthors = Das S, Jayaratne R, Barrett KE | title = The Role of Ion Transporters in the Pathophysiology of Infectious&nbsp;Diarrhea | journal = Cellular and Molecular Gastroenterology and Hepatology | volume = 6 | issue = 1 | pages = 33–45 | date = 2018 | pmid = 29928670 | pmc = 6007821 | doi = 10.1016/j.jcmgh.2018.02.009 }}</ref>
! Function &nbsp;!! Transporter
|-
|Absorption|| [[NHE]], [[SGLT1]], [[ENaC]], [[Downregulated-in-adenoma|DRA]]
|-
|Secretion||[[CaCC]], [[NKCC1]], [[CFTR]]
|-
|Absorption and secretion
||[[Sodium potassium ATPase]]
|}

===Evolution===
According to two researchers, [[Randolph M. Nesse|Nesse]] and [[George C. Williams (biologist)|Williams]], diarrhea may function as an evolved expulsion defense mechanism. As a result, if it is stopped, there might be a delay in recovery.<ref>{{cite book | vauthors = Williams G, Nesse RM |title=Why we get sick: the new science of Darwinian medicine |publisher=[[Vintage Books]] |location=New York |year=1996 |pages=36–38 |isbn=978-0-679-74674-4 }}</ref> They cite in support of this argument research published in 1973 that found that treating ''[[Shigella]]'' with the anti-diarrhea drug (Co-phenotrope, [[Lomotil]]) caused people to stay [[fever]]ish twice as long as those not so treated. The researchers indeed themselves observed that: "Lomotil may be contraindicated in shigellosis. Diarrhea may represent a defense mechanism".<ref>{{cite journal | vauthors = DuPont HL, Hornick RB | title = Adverse effect of lomotil therapy in shigellosis | journal = JAMA | volume = 226 | issue = 13 | pages = 1525–8 | date = December 1973 | pmid = 4587313 | doi = 10.1001/jama.226.13.1525 }}</ref>

== Diagnostic approach ==

The following types of diarrhea may indicate further investigation is needed:

* In infants
* Moderate or severe diarrhea in young children
* Associated with blood
* Continues for more than two days
* Associated non-cramping [[abdominal pain]], [[fever]], [[weight loss]], etc.
* In [[Traveler's diarrhea|travelers]]
* In food handlers, because of the potential to infect others;
* In institutions such as hospitals, child care centers, or geriatric and convalescent homes.

A severity score is used to aid diagnosis in children.<ref name="pmid2371542">{{cite journal | vauthors = Ruuska T, Vesikari T | title = Rotavirus disease in Finnish children: use of numerical scores for clinical severity of diarrhoeal episodes | journal = Scandinavian Journal of Infectious Diseases | volume = 22 | issue = 3 | pages = 259–67 | year = 1990 | pmid = 2371542 | doi = 10.3109/00365549009027046 }}</ref>

When diarrhea lasts for more than four weeks a number of further tests may be recommended including:<ref>{{cite journal | vauthors = Arasaradnam RP, Brown S, Forbes A, Fox MR, Hungin P, Kelman L, Major G, O'Connor M, Sanders DS, Sinha R, Smith SC, Thomas P, Walters JR | title = Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition | journal = Gut | volume = 67 | issue = 8 | pages = 1380–1399 | date = August 2018 | pmid = 29653941 | pmc = 6204957 | doi = 10.1136/gutjnl-2017-315909 }}</ref>

* [[Complete blood count]] and a [[ferritin]] if [[anemia]] is present
* [[Thyroid stimulating hormone]]
* [[Tissue transglutaminase]] for [[celiac disease]]
* Fecal [[calprotectin]] to exclude [[inflammatory bowel disease]]
* [[Stool test]]s for ova and parasites as well as for ''[[Clostridioides difficile (bacteria)|Clostridioides difficile]]''
* A [[colonoscopy]] or fecal immunochemical testing for cancer, including biopsies to detect [[microscopic colitis]]
* Testing for [[bile acid diarrhea]] with [[SeHCAT]], [[7α-hydroxy-4-cholesten-3-one]] or fecal [[bile acids]] depending on availability
* [[Hydrogen breath test]] looking for [[lactose intolerance]]
* Further tests if [[immunodeficiency]], [[pelvic radiation disease]] or [[small intestinal bacterial overgrowth]] suspected.

A 2019 guideline recommended that testing for ova and parasites was only needed in people who are at high risk though they recommend routine testing for [[giardia]].<ref name=Sma2019>{{cite journal | vauthors = Smalley W, Falck-Ytter C, Carrasco-Labra A, Wani S, Lytvyn L, Falck-Ytter Y | title = AGA Clinical Practice Guidelines on the Laboratory Evaluation of Functional Diarrhea and Diarrhea-Predominant Irritable Bowel Syndrome in Adults (IBS-D) | journal = Gastroenterology | volume = 157 | issue = 3 | pages = 851–854 | date = September 2019 | pmid = 31302098 | doi = 10.1053/j.gastro.2019.07.004 | doi-access = free }}</ref> [[Erythrocyte sedimentation rate]] (ESR) and [[C-reactive protein]] (CRP) were not recommended.<ref name=Sma2019/>

==Epidemiology==
[[File:Diarrhoeal diseases world map-Deaths per million persons-WHO2012.svg|thumb|upright=1.3|Deaths due to diarrhoeal diseases per million persons in 2012 {{Div col|small=yes|colwidth=10em}}{{legend|#ffff20|0–2}}{{legend|#ffe820|3–10}}{{legend|#ffd820|11–18}}{{legend|#ffc020|19–30}}{{legend|#ffa020|31–46}}{{legend|#ff9a20|47–80}}{{legend|#f08015|81–221}}{{legend|#e06815|222–450}}{{legend|#d85010|451–606}}{{legend|#d02010|607–1799}}{{div col end}}]]
[[File:Diarrhoeal diseases world map - DALY - WHO2004.svg|thumb|upright=1.3|[[Disability-adjusted life year]] for diarrhea per 100,000&nbsp;inhabitants in 2004<ref>{{cite web |url=https://www.who.int/entity/healthinfo/global_burden_disease/gbddeathdalycountryestimates2004.xls |title=Mortality and Burden of Disease Estimates for WHO Member States in 2004 |format=xls |work=[[World Health Organization]] |access-date=4 October 2020 |archive-date=28 August 2021 |archive-url=https://web.archive.org/web/20210828123901/https://www.who.int/healthinfo/global_burden_disease/gbddeathdalycountryestimates2004.xls |url-status=live }}</ref>{{Div col|small=yes|colwidth=10em}}
{{legend|#b3b3b3|no data}}
{{legend|#ffff65|<&nbsp;500}}
{{legend|#fff200|500–1000}}
{{legend|#ffdc00|1000–1500}}
{{legend|#ffc600|1500–2000}}
{{legend|#ffb000|2000–2500}}
{{legend|#ff9a00|2500–3000}}
{{legend|#ff8400|3000–3500}}
{{legend|#ff6e00|3500–4000}}
{{legend|#ff5800|4000–4500}}
{{legend|#ff4200|4500–5000}}
{{legend|#ff2c00|5000–6000}}
{{legend|#cb0000|>&nbsp;6000}}
{{div col end}}]]

Worldwide in 2004, approximately 2.5&nbsp;billion cases of diarrhea occurred, which resulted in 1.5&nbsp;million deaths among children under the age of five.<ref name=WHO2010a/> Greater than half of these were in Africa and South Asia.<ref name=WHO2010a/> This is down from a death rate of 4.5 million in 1980 for gastroenteritis.<ref name="Mandell">{{cite book | vauthors = Mandell GL, Bennett JE, Dolin R |title=Mandell's Principles and Practices of Infection Diseases |publisher=Churchill Livingstone |year=2004 |isbn=978-0-443-06643-6 |edition=6th |url=http://www.ppidonline.com/ |url-status=live |archive-url=https://web.archive.org/web/20131018175309/http://www.ppidonline.com/ |archive-date=18 October 2013 }}</ref> Diarrhea remains the second leading cause of [[infant mortality]] (16%) after [[pneumonia]] (17%) in this age group.<ref name=WHO2010a/>

The majority of such cases occur in the developing world, with over half of the recorded cases of childhood diarrhea occurring in [[Africa]] and [[Asia]], with 696 million and 1.2 billion cases, respectively, compared to only 480 million in the rest of the world.<ref>{{cite web |title=Diarrhoea: why children are still dying and what can be done |url= http://whqlibdoc.who.int/publications/2009/9789241598415_eng.pdf | publisher = World Health Organization |access-date=12 October 2013 |url-status=live |archive-url=https://web.archive.org/web/20131019153745/http://whqlibdoc.who.int/publications/2009/9789241598415_eng.pdf |archive-date=19 October 2013 }}</ref>

Infectious diarrhea resulted in about 0.7 million deaths in children under five years old in 2011 and 250 million lost school days.<ref name="UN2015" /><ref>{{cite journal | vauthors = Walker CL, Rudan I, Liu L, Nair H, Theodoratou E, Bhutta ZA, O'Brien KL, Campbell H, Black RE | title = Global burden of childhood pneumonia and diarrhoea | journal = Lancet | volume = 381 | issue = 9875 | pages = 1405–1416 | date = April 2013 | pmid = 23582727 | doi = 10.1016/S0140-6736(13)60222-6 | pmc = 7159282 }}</ref> In the Americas, diarrheal disease accounts for a total of 10% of deaths among children aged 1–59 months while in South East Asia, it accounts for 31.3% of deaths.<ref>{{cite journal | vauthors = Walker CL, Aryee MJ, Boschi-Pinto C, Black RE | title = Estimating diarrhea mortality among young children in low and middle income countries | journal = PLOS ONE | volume = 7 | issue = 1 | article-number = e29151 | year = 2012 | pmid = 22235266 | pmc = 3250411 | doi = 10.1371/journal.pone.0029151 | bibcode = 2012PLoSO...729151F | doi-access = free }}</ref> It is estimated that around 21% of child mortalities in developing countries are due to diarrheal disease.<ref name='c'>{{cite journal | vauthors = Kosek M, Bern C, Guerrant RL | title = The global burden of diarrhoeal disease, as estimated from studies published between 1992 and 2000 | journal = Bulletin of the World Health Organization | volume = 81 | issue = 3 | pages = 197–204 | year = 2003 | pmid = 12764516 | pmc = 2572419 }}</ref>

The [[World Health Organization]] has reported that "deaths due to diarrhoeal diseases have dropped by 45%, from sixth leading cause of death in 2000 to thirteenth in 2021."<ref>{{Cite web |title=The top 10 causes of death |url=https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death |access-date=2024-08-12 |website=www.who.int |language=en |archive-date=24 September 2021 |archive-url=https://web.archive.org/web/20210924191646/https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death |url-status=live }}</ref>

Even though diarrhea is best known in humans, it affects many other species, notably among [[Primate|primates]].<ref name="Hird et al. 1984">{{cite journal |last1=Hird |first1=D W |last2=Anderson |first2=J H |last3=Bielitzki |first3=J T |title=Diarrhea in nonhuman primates: a survey of primate colonies for incidence rates and clinical opinion |journal=Laboratory Animal Science |date=1 October 1984 |volume=34 |issue=5 |pages=465–470 |pmid=6513506 |url=https://europepmc.org/article/med/6513506 |issn=0023-6764 |access-date=4 July 2024 |archive-date=15 April 2024 |archive-url=https://web.archive.org/web/20240415155247/https://europepmc.org/article/med/6513506 |url-status=live }}</ref> The [[Appendix (anatomy)|cecal appendix]], when present, appears to afford some protection against diarrhea to young primates.<ref name="Collard et al. 2023">{{cite journal |last1=Collard |first1=Maxime K. |last2=Bardin |first2=Jérémie |last3=Marquet |first3=Bertille |last4=Laurin |first4=Michel |last5=Ogier-Denis |first5=Éric |title=Correlation between the presence of a cecal appendix and reduced diarrhea severity in primates: new insights into the presumed function of the appendix |journal=Scientific Reports |date=23 September 2023 |volume=13 |issue=1 |page=15897 |doi=10.1038/s41598-023-43070-5 |pmid=37741857 |language=en |issn=2045-2322|pmc=10517977 |bibcode=2023NatSR..1315897C }}</ref>

==Prevention==

===Sanitation===
{{Further|WASH#Health aspects}}
Numerous studies have shown that improvements in drinking water and sanitation ([[WASH]]) lead to decreased risks of diarrhoea.<ref name=":0">{{cite journal | vauthors = Wolf J, Prüss-Ustün A, Cumming O, Bartram J, Bonjour S, Cairncross S, Clasen T, Colford JM, Curtis V, De France J, Fewtrell L, Freeman MC, Gordon B, Hunter PR, Jeandron A, Johnston RB, Mäusezahl D, Mathers C, Neira M, Higgins JP | title = Assessing the impact of drinking water and sanitation on diarrhoeal disease in low- and middle-income settings: systematic review and meta-regression | journal = Tropical Medicine & International Health | volume = 19 | issue = 8 | pages = 928–42 | date = August 2014 | pmid = 24811732 | doi = 10.1111/tmi.12331 | s2cid = 22903164 | url = https://ueaeprints.uea.ac.uk/51912/1/Wolf_2014_Assessing_impact_of_drinking_water.pdf | doi-access = free | access-date = 17 December 2019 | archive-date = 13 April 2020 | archive-url = https://web.archive.org/web/20200413184758/https://ueaeprints.uea.ac.uk/id/eprint/51912/1/Wolf_2014_Assessing_impact_of_drinking_water.pdf | url-status = live }}</ref> Such improvements might include for example use of water filters, provision of high-quality [[drinking water|piped water]] and [[sanitary sewer|sewer]] connections.<ref name=":0" />

In institutions, communities, and households, interventions that promote [[hand washing]] with soap lead to significant reductions in the incidence of diarrhea.<ref name=":1">{{cite journal | vauthors = Ejemot-Nwadiaro RI, Ehiri JE, Arikpo D, Meremikwu MM, Critchley JA | title = Hand-washing promotion for preventing diarrhoea | journal = The Cochrane Database of Systematic Reviews | volume = 12 | article-number = CD004265 | date = January 2021 | issue = 1 | pmid = 33539552 | pmc = 8094449 | doi = 10.1002/14651858.CD004265.pub4 }}</ref> The same applies to preventing [[open defecation]] at a community-wide level and providing access to [[improved sanitation]].<ref name="UN2015">{{cite web|title=Call to action on sanitation|url=http://sanitationdrive2015.org/wp-content/uploads/2013/03/DSG_Sanitation_Fast-Facts_final.pdf|website=United Nations|access-date=15 August 2014|url-status=usurped|archive-url=https://web.archive.org/web/20140819084624/http://sanitationdrive2015.org/wp-content/uploads/2013/03/DSG_Sanitation_Fast-Facts_final.pdf|archive-date=19 August 2014}}</ref><ref>{{cite journal | vauthors = Spears D, Ghosh A, Cumming O | title = Open defecation and childhood stunting in India: an ecological analysis of new data from 112 districts | journal = PLOS ONE | volume = 8 | issue = 9 | article-number = e73784 | year = 2013 | pmid = 24066070 | pmc = 3774764 | doi = 10.1371/journal.pone.0073784 | doi-access = free | bibcode = 2013PLoSO...873784S }}</ref> This includes use of [[toilet]]s and implementation of the entire [[sanitation]] chain connected to the toilets (collection, transport, disposal or reuse of [[human waste|human excreta]]).

There is limited evidence that safe disposal of child or adult feces can prevent diarrheal disease.<ref>{{cite journal | vauthors = Majorin F, Torondel B, Ka Seen Chan G, Clasen T | title = Interventions to improve disposal of child faeces for preventing diarrhoea and soil-transmitted helminth infection | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | article-number = CD011055 | date = September 2019 | issue = 9 | pmid = 31549742 | pmc = 6757260 | doi = 10.1002/14651858.CD011055.pub2 | collaboration = Cochrane Infectious Diseases Group }}</ref><ref>{{cite journal | vauthors = Clasen TF, Bostoen K, Schmidt WP, Boisson S, Fung IC, Jenkins MW, Scott B, Sugden S, Cairncross S | title = Interventions to improve disposal of human excreta for preventing diarrhoea | journal = The Cochrane Database of Systematic Reviews | issue = 6 | article-number = CD007180 | date = June 2010 | volume = 2010 | pmid = 20556776 | pmc = 6532559 | doi = 10.1002/14651858.CD007180.pub2 | collaboration = Cochrane Infectious Diseases Group }}</ref>

====Hand washing====
Basic sanitation techniques can have a profound effect on the transmission of diarrheal disease. The implementation of hand washing using soap and water, for example, has been experimentally shown to reduce the incidence of disease by approximately 30–48%.<ref>{{cite journal | vauthors = Curtis V, Cairncross S | title = Effect of washing hands with soap on diarrhoea risk in the community: a systematic review | journal = The Lancet. Infectious Diseases | volume = 3 | issue = 5 | pages = 275–81 | date = May 2003 | pmid = 12726975 | doi = 10.1016/S1473-3099(03)00606-6 }}</ref><ref>{{cite journal | vauthors = Cairncross S, Hunt C, Boisson S, Bostoen K, Curtis V, Fung IC, Schmidt WP | title = Water, sanitation and hygiene for the prevention of diarrhoea | journal = International Journal of Epidemiology | volume = 39 | issue = Suppl 1 | pages = i193-205 | date = April 2010 | pmid = 20348121 | pmc = 2845874 | doi = 10.1093/ije/dyq035 }}</ref><ref name=":1" /> Hand washing in developing countries, however, is compromised by poverty as acknowledged by the [[Centers for Disease Control and Prevention|CDC]]: "Handwashing is integral to disease prevention in all parts of the world; however, access to soap and water is limited in a number of less developed countries. This lack of access is one of many challenges to proper hygiene in less developed countries." Solutions to this barrier require the implementation of educational programs that encourage sanitary behaviours.<ref>{{cite web|title=Diarrheal Diseases in Less Developed Countries|url=https://www.cdc.gov/healthywater/hygiene/ldc/diarrheal_diseases.html|work=CDC|access-date=28 October 2013|url-status=live|archive-url=https://web.archive.org/web/20131104042634/http://www.cdc.gov/healthywater/hygiene/ldc/diarrheal_diseases.html|archive-date=4 November 2013}}</ref>

====Water====
Given that water contamination is a major means of transmitting diarrheal disease, efforts to provide clean [[water supply]] and [[improved sanitation]] have the potential to dramatically cut the rate of disease incidence. In fact, it has been proposed that we might expect an 88% reduction in child mortality resulting from diarrheal disease as a result of improved water sanitation and hygiene.<ref name="Brown 629–34"/><ref>{{cite journal | vauthors = Black RE, Morris SS, Bryce J | s2cid = 14509705 | title = Where and why are 10 million children dying every year? | journal = Lancet | volume = 361 | issue = 9376 | pages = 2226–34 | date = June 2003 | pmid = 12842379 | doi = 10.1016/S0140-6736(03)13779-8 }}</ref> Similarly, a meta-analysis of numerous studies on improving water supply and sanitation shows a 22–27% reduction in disease incidence, and a 21–30% reduction in mortality rate associated with diarrheal disease.<ref>{{cite journal | vauthors = Esrey SA, Feachem RG, Hughes JM | title = Interventions for the control of diarrhoeal diseases among young children: improving water supplies and excreta disposal facilities | journal = Bulletin of the World Health Organization | volume = 63 | issue = 4 | pages = 757–72 | year = 1985 | pmid = 3878742 | pmc = 2536385 }}</ref>

Chlorine treatment of water, for example, has been shown to reduce both the risk of diarrheal disease, and of contamination of stored water with diarrheal pathogens.<ref>{{cite journal | vauthors = Arnold BF, Colford JM | title = Treating water with chlorine at point-of-use to improve water quality and reduce child diarrhea in developing countries: a systematic review and meta-analysis | journal = The American Journal of Tropical Medicine and Hygiene | volume = 76 | issue = 2 | pages = 354–64 | date = February 2007 | pmid = 17297049 | doi = 10.4269/ajtmh.2007.76.354 | doi-access = free }}</ref>

===Vaccination===
Immunization against the pathogens that cause diarrheal disease is a viable prevention strategy, however it does require targeting certain pathogens for vaccination. In the case of Rotavirus, which was responsible for around 6% of diarrheal episodes and 20% of diarrheal disease deaths in the children of developing countries, use of a Rotavirus vaccine in trials in 1985 yielded a slight (2–3%) decrease in total diarrheal disease incidence, while reducing overall mortality by 6–10%. Similarly, a Cholera vaccine showed a strong reduction in morbidity and mortality, though the overall impact of vaccination was minimal as Cholera is not one of the major causative pathogens of diarrheal disease.<ref>{{cite journal | vauthors = de Zoysa I, Feachem RG | title = Interventions for the control of diarrhoeal diseases among young children: rotavirus and cholera immunization | journal = Bulletin of the World Health Organization | volume = 63 | issue = 3 | pages = 569–83 | year = 1985 | pmid = 3876173 | pmc = 2536413 }}</ref> Since this time, more effective vaccines have been developed that have the potential to save many thousands of lives in developing nations, while reducing the overall cost of treatment, and the costs to society.<ref>{{cite journal | vauthors = Rheingans RD, Antil L, Dreibelbis R, Podewils LJ, Bresee JS, Parashar UD | title = Economic costs of rotavirus gastroenteritis and cost-effectiveness of vaccination in developing countries | journal = The Journal of Infectious Diseases | volume = 200 | pages = S16-27 | date = November 2009 | issue = Suppl 1 | pmid = 19817595 | doi = 10.1086/605026 | doi-access = free | url = http://libres.uncg.edu/ir/asu/f/Rheingans_Richard_2009_Economic_Costs_of_Rotavirus_orig.pdf | access-date = 27 February 2024 | archive-date = 27 February 2024 | archive-url = https://web.archive.org/web/20240227043727/http://libres.uncg.edu/ir/asu/f/Rheingans_Richard_2009_Economic_Costs_of_Rotavirus_orig.pdf | url-status = live }}</ref><ref>{{cite book|title=Oral cholera vaccines in mass immunization campaigns |year=2010 |publisher=WHO |isbn=978-92-4-150043-2 |pages=6–8 |url= http://whqlibdoc.who.int/publications/2010/9789241500432_eng.pdf |url-status=live |archive-url= https://web.archive.org/web/20140903045312/http://whqlibdoc.who.int/publications/2010/9789241500432_eng.pdf |archive-date=3 September 2014 }}</ref>

[[Rotavirus vaccine]] decreases the rates of diarrhea in a population.<ref name=WHO2010a/><ref>{{cite journal | vauthors = Soares-Weiser K, Goldberg E, Tamimi G, Pitan OC, Leibovici L | title = Rotavirus vaccine for preventing diarrhoea | journal = The Cochrane Database of Systematic Reviews | issue = 1 | article-number = CD002848 | date = 2004-01-26 | volume = 2004 | pmid = 14973994 | pmc = 6532746 | doi = 10.1002/14651858.CD002848.pub2  | collaboration = Cochrane Infectious Diseases Group }}</ref> New vaccines against rotavirus, ''Shigella'', [[Enterotoxigenic Escherichia coli|Enterotoxigenic ''Escherichia coli'' (ETEC)]], and cholera are under development, as well as other causes of infectious diarrhea.{{medcn|date=January 2015}}

===Nutrition===
Dietary deficiencies in developing countries can be combated by promoting better eating practices. Zinc supplementation proved successful showing a significant decrease in the incidence of diarrheal disease compared to a control group.<ref>{{cite journal | vauthors = Black RE | title = Zinc deficiency, infectious disease and mortality in the developing world | journal = The Journal of Nutrition | volume = 133 | issue = 5 Suppl 1 | pages = 1485S–9S | date = May 2003 | pmid = 12730449 | doi = 10.1093/jn/133.5.1485S | doi-access = free }}</ref><ref>{{cite journal | vauthors = Bhutta ZA, Black RE, Brown KH, Gardner JM, Gore S, Hidayat A, Khatun F, Martorell R, Ninh NX, Penny ME, Rosado JL, Roy SK, Ruel M, Sazawal S, Shankar A | title = Prevention of diarrhea and pneumonia by zinc supplementation in children in developing countries: pooled analysis of randomized controlled trials. Zinc Investigators' Collaborative Group | journal = The Journal of Pediatrics | volume = 135 | issue = 6 | pages = 689–97 | date = December 1999 | pmid = 10586170 | doi = 10.1016/S0022-3476(99)70086-7 | doi-access = free }}</ref> The majority of the literature suggests that vitamin A supplementation is advantageous in reducing disease incidence.<ref>{{cite journal | vauthors = Mayo-Wilson E, Imdad A, Herzer K, Yakoob MY, Bhutta ZA | title = Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis | journal = BMJ | volume = 343 | article-number = d5094 | date = August 2011 | pmid = 21868478 | pmc = 3162042 | doi = 10.1136/bmj.d5094 }}</ref> Development of a supplementation strategy should take into consideration the fact that vitamin A supplementation was less effective in reducing diarrhea incidence when compared to vitamin A and zinc supplementation, and that the latter strategy was estimated to be significantly more cost effective.<ref>{{cite journal | vauthors = Chhagan MK, Van den Broeck J, Luabeya KK, Mpontshane N, Bennish ML | title = Cost of childhood diarrhoea in rural South Africa: exploring cost-effectiveness of universal zinc supplementation | journal = Public Health Nutrition | volume = 17 | issue = 9 | pages = 2138–45 | date = September 2014 | pmid = 23930984 | doi = 10.1017/S1368980013002152 | doi-access = free | pmc = 11108711 }}</ref>

====Breastfeeding====
Breastfeeding practices have been shown to have a dramatic effect on the incidence of diarrheal disease in poor populations. Studies across a number of developing nations have shown that those who receive [[Breastfeeding#Duration and exclusivity|exclusive breastfeeding]] during their first 6 months of life are better protected against infection with diarrheal diseases.<ref>{{cite journal | s2cid = 30952224 | title = Effect of breastfeeding on infant and child mortality due to infectious diseases in less developed countries: a pooled analysis. WHO Collaborative Study Team on the Role of Breastfeeding on the Prevention of Infant Mortality | journal = Lancet | volume = 355 | issue = 9202 | pages = 451–5 | date = February 2000 | pmid = 10841125 | doi = 10.1016/S0140-6736(00)82011-5 }}</ref> One study in Brazil found that non-breastfed infants were 14 times more likely to die from diarrhea than exclusively breastfed infants.<ref name=Lawrence2016>{{cite book | vauthors = Lawrence R | title=Breastfeeding: a guide for the medical profession, 8th edition | publisher=Elsevier | location=Philadelphia, PA | year=2016 | isbn=978-0-323-35776-0 | page = 28}}</ref> Exclusive breastfeeding is currently recommended for the first six months of an infant's life by the [[World Health Organization|WHO]],<ref>{{cite web| vauthors = Sguassero Y |title=Optimal duration of exclusive breastfeeding: RHL commentary|url=http://apps.who.int/rhl/pregnancy_childbirth/care_after_childbirth/yscom/en/|publisher=WHO|access-date=14 October 2013|archive-url=https://web.archive.org/web/20131103115327/http://apps.who.int/rhl/pregnancy_childbirth/care_after_childbirth/yscom/en/|archive-date=3 November 2013}}</ref><ref name="World Health Organization 2017">{{cite web | title=Infant and young child feeding | website=World Health Organization | date=3 October 2017 | url=https://www.who.int/mediacentre/factsheets/fs342/en/ | access-date=5 January 2018 | archive-date=8 February 2015 | archive-url=https://web.archive.org/web/20150208145357/http://www.who.int/mediacentre/factsheets/fs342/en/ | url-status=live }}</ref> with continued breastfeeding until at least two years of age.<ref name="World Health Organization 2017"/>

===Others===
[[Probiotics]] decrease the risk of diarrhea in those taking [[antibiotics]].<ref>{{cite journal | vauthors = Hempel S, Newberry SJ, Maher AR, Wang Z, Miles JN, Shanman R, Johnsen B, Shekelle PG | title = Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis | journal = JAMA: The Journal of the American Medical Association | volume = 307 | issue = 18 | pages = 1959–69 | date = May 2012 | pmid = 22570464 | doi = 10.1001/jama.2012.3507 | doi-access =  }}</ref> [[Insecticide]] spraying may reduce fly numbers and the risk of diarrhea in children in a setting where there is seasonal variations in fly numbers throughout the year.<ref>{{cite journal | vauthors = Das JK, Hadi YB, Salam RA, Hoda M, Lassi ZS, Bhutta ZA | title = Fly control to prevent diarrhoea in children | journal = The Cochrane Database of Systematic Reviews | volume = 12 | article-number = CD011654 | date = December 2018 | issue = 12 | pmid = 30556598 | pmc = 6302900 | doi = 10.1002/14651858.CD011654.pub2 | collaboration = Cochrane Infectious Diseases Group }}</ref>

==Management==
In many cases of diarrhea, replacing lost fluid and salts is the only treatment needed. This is usually by mouth – [[oral rehydration therapy]] – or, in severe cases, [[intravenously]].<ref name=WHO2010a/> Diet restrictions such as the [[BRAT diet]] are no longer recommended.<ref>{{cite journal | vauthors = King CK, Glass R, Bresee JS, Duggan C | title = Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy | journal = MMWR. Recommendations and Reports | volume = 52 | issue = RR-16 | pages = 1–16 | date = November 2003 | pmid = 14627948 | url = https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5216a1.htm | archive-url = https://web.archive.org/web/20141028174056/http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5216a1.htm | author5 = Centers for Disease Control Prevention | url-status = live | archive-date = 28 October 2014 }}</ref> Research does not support the limiting of milk to children as doing so has no effect on duration of diarrhea.<ref>{{cite web |url=http://www.bestbets.org/bets/bet.php?id=1728 |title=BestBets: Does Withholding milk feeds reduce the duration of diarrhoea in children with acute gastroenteritis? |url-status=live |archive-url=https://web.archive.org/web/20090504105749/http://www.bestbets.org/bets/bet.php?id=1728 |archive-date=4 May 2009 }}</ref> To the contrary, WHO recommends that children with diarrhea continue to eat as sufficient nutrients are usually still absorbed to support continued growth and weight gain, and that continuing to eat also speeds up recovery of normal intestinal functioning.<ref name=WHOtreatmentdiarrhoea2005/> CDC recommends that children and adults with cholera also continue to eat.<ref name = CDCmanualCholera/> There is no evidence that early refeeding in children can cause an increase in inappropriate use of intravenous fluid, episodes of vomiting, and risk of having persistent diarrhea.<ref>{{cite journal | vauthors = Gregorio GV, Dans LF, Silvestre MA | title = Early versus Delayed Refeeding for Children with Acute Diarrhoea | journal = The Cochrane Database of Systematic Reviews | issue = 7 | article-number = CD007296 | date = July 2011 | volume = 2011 | pmid = 21735409 | pmc = 6532715 | doi = 10.1002/14651858.CD007296.pub2 | collaboration = Cochrane Infectious Diseases Group }}</ref>

Medications such as [[loperamide]] (Imodium) and [[bismuth subsalicylate]] may be beneficial; however they may be [[contraindicated]] in certain situations.<ref name="pmid18192963">{{cite journal | vauthors = Schiller LR | title = Management of diarrhea in clinical practice: strategies for primary care physicians | journal = Reviews in Gastroenterological Disorders | volume = 7 | issue = Suppl 3 | pages = S27-38 | year = 2007 | pmid = 18192963 }}</ref>

===Fluids===
{{See also|Management of dehydration}}
[[File:Cholera rehydration nurses.jpg|thumb|A person consuming oral rehydration solution]]
[[Oral rehydration therapy|Oral rehydration solution (ORS)]] (a slightly sweetened and salty water) can be used to prevent dehydration. Standard home solutions such as salted rice water, salted yogurt drinks, vegetable and chicken soups with salt can be given. Home solutions such as water in which cereal has been cooked, unsalted soup, green coconut water, weak tea (unsweetened), and unsweetened fresh fruit juices can have from half a teaspoon to full teaspoon of salt (from one-and-a-half to three grams) added per liter. Clean plain water can also be one of several fluids given.<ref name=WHOtreatmentdiarrhoea2005/> There are commercial solutions such as [[Pedialyte]], and relief agencies such as [[UNICEF]] widely distribute packets of salts and sugar. A WHO publication for physicians recommends a homemade ORS consisting of one liter water with one teaspoon salt (3 grams) and two tablespoons sugar (18 grams) added<ref name=WHOtreatmentdiarrhoea2005/> (approximately the "taste of tears"<ref name=2010WorldCupTravellersGuide>[https://www.who.int/topics/test/food_safety/safe_food_travel.pdf A Guide on Safe Food for Travellers] {{webarchive|url=https://web.archive.org/web/20120709034248/http://www.who.int/topics/test/food_safety/safe_food_travel.pdf |date=9 July 2012 }}, Welcome to South Africa, Host to the 2010 FIFA World Cup (bottom left of page 1).</ref>). Rehydration Project recommends adding the same amount of sugar but only one-half a teaspoon of salt, stating that this more dilute approach is less risky with very little loss of effectiveness.<ref name=RehydrationProject>Rehydration Project, {{cite web |url=http://rehydrate.org/ |title=Diarrhoea, Diarrhea, Dehydration, Oral Rehydration, Mother and Child Nutrition, Water, Sanitation, Hygiene – Rehydration Project |access-date=22 June 2015 |url-status=live |archive-url=https://web.archive.org/web/20150608064953/http://rehydrate.org/ |archive-date=8 June 2015 }} Homemade Oral Rehydration Solution Recipe.</ref> Both agree that drinks with too much sugar or salt can make dehydration worse.<ref name=WHOtreatmentdiarrhoea2005/><ref name=RehydrationProject/>

Appropriate amounts of supplemental zinc and potassium should be added if available. But the availability of these should not delay rehydration. As WHO points out, the most important thing is to begin preventing dehydration as early as possible.<ref name=WHOtreatmentdiarrhoea2005/> In another example of prompt ORS hopefully preventing dehydration, CDC recommends for the treatment of cholera continuing to give Oral Rehydration Solution during travel to medical treatment.<ref name=CDCmanualCholera>[https://www.cdc.gov/haiticholera/pdf/chw_trainingmaterialsforcholera.pdf Community Health Worker Training Materials for Cholera Prevention and Control] {{webarchive|url=https://web.archive.org/web/20111020070810/http://www.cdc.gov/haiticholera/pdf/chw_trainingmaterialsforcholera.pdf |date=20 October 2011 }}, CDC, slides at back are dated 17 November 2010. Page 7 states "...{{nbsp}} Continue to breastfeed your baby if the baby has watery diarrhea, even when traveling to get treatment. Adults and older children should continue to eat frequently."</ref>

Vomiting often occurs during the first hour or two of treatment with ORS, especially if a child drinks the solution too quickly, but this seldom prevents successful rehydration since most of the fluid is still absorbed. WHO recommends that if a child vomits, to wait five or ten minutes and then start to give the solution again more slowly.<ref name=WHOtreatmentdiarrhoea2005/>

Drinks especially high in simple sugars, such as [[soft drinks]] and fruit juices, are not recommended in children under five as they may ''increase'' dehydration. A too rich solution in the gut draws water from the rest of the body, just as if the person were to drink sea water.<ref name=WHOtreatmentdiarrhoea2005/><ref name=NICE2009>{{cite web|title=Management of acute diarrhoea and vomiting due to gastroenteritis in children under 5|url=http://guidance.nice.org.uk/CG84|work=National Institute of Clinical Excellence|date=April 2009|url-status=live|archive-url=https://web.archive.org/web/20090802094158/http://guidance.nice.org.uk/CG84|archive-date=2 August 2009}}</ref> Plain water may be used if more specific and effective ORT preparations are unavailable or are not palatable.<ref name=NICE2009/> Additionally, a mix of both plain water and drinks perhaps too rich in sugar and salt can alternatively be given to the same person, with the goal of providing a medium amount of sodium overall.<ref name=WHOtreatmentdiarrhoea2005/> A [[nasogastric tube]] can be used in young children to administer fluids if warranted.<ref name=Webb2005>{{cite journal | vauthors = Webb A, Starr M | title = Acute gastroenteritis in children | journal = Australian Family Physician | volume = 34 | issue = 4 | pages = 227–31 | date = April 2005 | pmid = 15861741 }}</ref>

===Eating===
The WHO recommends a child with diarrhea continue to be fed. Continued feeding speeds the recovery of normal intestinal function. In contrast, children whose food is restricted have diarrhea of longer duration and recover intestinal function more slowly. The WHO states "Food should ''never'' be withheld and the child's usual foods should ''not'' be diluted. Breastfeeding should ''always'' be continued."<ref name=WHOtreatmentdiarrhoea2005/> In the specific example of cholera, the CDC makes the same recommendation.<ref name = CDCmanualCholera/> Breast-fed infants with diarrhea often choose to breastfeed more, and should be encouraged to do so.<ref name=WHOtreatmentdiarrhoea2005/> In young children who are not breast-fed and live in the developed world, a lactose-free diet may be useful to speed recovery.<ref>{{cite journal | vauthors = MacGillivray S, Fahey T, McGuire W | title = Lactose avoidance for young children with acute diarrhoea | journal = The Cochrane Database of Systematic Reviews | volume = 2013 | issue = 10 | article-number = CD005433 | date = October 2013 | pmid = 24173771 | pmc = 4276385 | doi = 10.1002/14651858.CD005433.pub2 }}</ref>
Eating food containing [[soluble fibre]] may help, but insoluble fibre might make it worse.<ref>{{cite web |url=https://www.webmd.com/digestive-disorders/chronic-diarrhea-16/diarrhea-more-fiber |title=The Facts About Fiber |access-date=25 January 2020 |archive-date=27 July 2020 |archive-url=https://web.archive.org/web/20200727012104/https://www.webmd.com/digestive-disorders/chronic-diarrhea-16/diarrhea-more-fiber |url-status=deviated }}</ref>

===Medications===
{{Main article|Antidiarrhoeal}}
Antidiarrheal agents can be classified into four different groups: antimotility, antisecretory, adsorbent, and anti-infectious.<ref name=Diosmectite2009>{{cite journal | vauthors=Guarino A, Lo Vecchio A, Pirozzi MR |s2cid=56519371 |title=Clinical role of diosmectite in the management of diarrhea. |journal=Expert Opin Drug Metab Toxicol |date=2009 |volume=5 |issue=4 |pages=433–440 |doi=10.1517/17425250902865594|pmid=19379128 }}</ref> While [[antibiotic]]s are beneficial in certain types of acute diarrhea, they are usually not used except in specific situations.<ref>{{cite journal | vauthors = Dryden MS, Gabb RJ, Wright SK | title = Empirical treatment of severe acute community-acquired gastroenteritis with ciprofloxacin | journal = Clinical Infectious Diseases | volume = 22 | issue = 6 | pages = 1019–25 | date = June 1996 | pmid = 8783703 | doi = 10.1093/clinids/22.6.1019 | doi-access = free }}</ref><ref name=CE08/> There are concerns that antibiotics may increase the risk of [[hemolytic uremic syndrome]] in people infected with [[Escherichia coli O157:H7|''Escherichia coli'' O157:H7]].<ref>{{cite journal | vauthors = Wong CS, Jelacic S, Habeeb RL, Watkins SL, Tarr PI | title = The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections | journal = The New England Journal of Medicine | volume = 342 | issue = 26 | pages = 1930–6 | date = June 2000 | pmid = 10874060 | pmc = 3659814 | doi = 10.1056/NEJM200006293422601 }}</ref> In resource-poor countries, treatment with antibiotics may be beneficial.<ref name=CE08>{{cite journal | vauthors = de Bruyn G | title = Diarrhoea in adults (acute) | journal = BMJ Clinical Evidence | volume = 2008 | page = 0901 | date = March 2008 | pmid = 19450323 | pmc = 2907942 }}</ref> However, some bacteria are developing [[antibiotic resistance]], particularly ''Shigella''.<ref>{{cite web |url=https://www.who.int/vaccine_research/diseases/diarrhoeal/en/index6.html |title=Diarrhoeal Diseases |date=February 2009 |work=World Health Organization |archive-url=https://web.archive.org/web/20081215123745/http://www.who.int/vaccine_research/diseases/diarrhoeal/en/index6.html |archive-date=15 December 2008 }}</ref> Antibiotics can also cause diarrhea, and [[antibiotic-associated diarrhea]] is the most common adverse effect of treatment with general antibiotics.

While bismuth compounds ([[Pepto-Bismol]]) decreased the number of bowel movements in those with travelers' diarrhea, they do not decrease the length of illness.<ref>{{cite journal | vauthors = DuPont HL, Ericsson CD, Farthing MJ, Gorbach S, Pickering LK, Rombo L, Steffen R, Weinke T | title = Expert review of the evidence base for self-therapy of travelers' diarrhea | journal = Journal of Travel Medicine | volume = 16 | issue = 3 | pages = 161–71 | year = 2009 | pmid = 19538576 | doi = 10.1111/j.1708-8305.2009.00300.x | doi-access = free }}</ref> Anti-motility agents like [[loperamide]] are also effective at reducing the number of stools but not the duration of disease.<ref name=NEJM2014/> These agents should be used only if bloody diarrhea is not present.<ref>{{cite journal | vauthors = Pawlowski SW, Warren CA, Guerrant R | title = Diagnosis and treatment of acute or persistent diarrhea | journal = Gastroenterology | volume = 136 | issue = 6 | pages = 1874–86 | date = May 2009 | pmid = 19457416 | pmc = 2723735 | doi = 10.1053/j.gastro.2009.02.072 }}</ref>

[[Diosmectite]], a natural aluminomagnesium silicate clay, is effective in alleviating symptoms of acute diarrhea in children,<ref>{{cite journal | vauthors = Dupont C, Vernisse B | title = Anti-diarrheal effects of diosmectite in the treatment of acute diarrhea in children: a review | journal = Paediatric Drugs | volume = 11 | issue = 2 | pages = 89–99 | date = 2009 | pmid = 19301931 | doi = 10.2165/00148581-200911020-00001 | pmc = 7100234 }}</ref> and also has some effects in chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea.<ref name="pmid26576135"/> Another absorbent agent used for the treatment of mild diarrhea is [[kaopectate]].

[[Racecadotril]] an antisecretory medication may be used to treat diarrhea in children and adults.<ref name=Diosmectite2009/> It has better tolerability than [[loperamide]], as it causes less [[constipation]] and [[flatulence]].<ref name="Arzneistoff-Profile">{{cite book|title=Arzneistoff-Profile| year = 1982 | veditors = Dinnendahl V, Fricke U |publisher=Govi Pharmazeutischer Verlag|location=Eschborn, Germany|isbn=978-3-7741-9846-3|language=de}}</ref> However, it has little benefit in improving acute diarrhea in children.<ref>{{cite journal | vauthors = Liang Y, Zhang L, Zeng L, Gordon M, Wen J | title = Racecadotril for acute diarrhoea in children | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | article-number = CD009359 | date = December 2019 | issue = 12 | pmid = 31858591 | pmc = 6923519 | doi = 10.1002/14651858.CD009359.pub2 | collaboration = Cochrane Infectious Diseases Group }}</ref>

[[Bile acid sequestrants]] such as [[cholestyramine]] can be effective in chronic diarrhea due to [[bile acid malabsorption]]. Therapeutic trials of these drugs are indicated in chronic diarrhea if bile acid malabsorption cannot be diagnosed with a specific test, such as [[SeHCAT]] retention.<ref>{{cite journal | vauthors = Wilcox C, Turner J, Green J | title = Systematic review: the management of chronic diarrhoea due to bile acid malabsorption | journal = Alimentary Pharmacology & Therapeutics | volume = 39 | issue = 9 | pages = 923–39 | date = May 2014 | pmid = 24602022 | doi = 10.1111/apt.12684 | s2cid = 12016216 | doi-access = free }}</ref>

===Alternative therapies===

Green bananas improved recovery, reduced dehydration and prevented prolonged diarrhea in children with diarrhea.<ref>{{cite journal |last1=Ghitha |first1=Nida |last2=Larasati |first2=Anjani |last3=Satari |first3=Heidi |last4=Maharani Indira |first4=Fiona |last5=Devaera |first5=Yoga |last6=Gayatri |first6=Pramita |title=The role of green banana in the dietary management of children with diarrhea: a systematic review and meta analysis |journal=Archives of Pediatric Gastroenterology, Hepatology, and Nutrition |date=31 Aug 2025 |volume=4 |issue=3 |page=98-110 |doi=10.58427/apghn.4.3.2025.98-110 |doi-access=free }}</ref> The benefit was attributed to its production of [[short-chain fatty acids]] in the colon from its [[resistant starch]] content, which enhances colonic water and electrolyte absorption.  

Zinc supplementation may benefit children over six months old with diarrhea in areas with high rates of malnourishment or zinc deficiency.<ref>{{cite journal | vauthors = Lazzerini M, Wanzira H | title = Oral zinc for treating diarrhoea in children | journal = The Cochrane Database of Systematic Reviews | volume = 12 | issue = 12 | article-number = CD005436 | date = December 2016 | pmid = 27996088 | pmc = 5450879 | doi = 10.1002/14651858.CD005436.pub5 }}</ref> This supports the World Health Organization guidelines for zinc, but not in the very young.

A Cochrane Review from 2020 concludes that [[probiotic]]s make little or no difference to people who have diarrhea lasting 2 days or longer and that there is no proof that they reduce its duration.<ref name="pmid33295643">{{cite journal |vauthors=Collinson S, Deans A, Padua-Zamora A, Gregorio GV, Li C, Dans LF, Allen SJ |date=December 2020 |title=Probiotics for treating acute infectious diarrhoea |journal=The Cochrane Database of Systematic Reviews |volume=2020 |issue=12 |article-number= CD003048|doi=10.1002/14651858.CD003048.pub4 |pmc=8166250 |pmid=33295643}}</ref> The [[probiotic]] ''[[Lactobacillus]]'' can help prevent [[antibiotic-associated diarrhea]] in adults but possibly not children.<ref>{{cite journal | vauthors = Kale-Pradhan PB, Jassal HK, Wilhelm SM | title = Role of Lactobacillus in the prevention of antibiotic-associated diarrhea: a meta-analysis | journal = Pharmacotherapy | volume = 30 | issue = 2 | pages = 119–26 | date = February 2010 | pmid = 20099986 | doi = 10.1592/phco.30.2.119 | s2cid = 21836205 }}</ref> For those with [[lactose intolerance]], taking digestive [[enzyme]]s containing [[lactase]] when consuming dairy products often improves symptoms.

== See also ==
{{Portal|Medicine}}

* {{annotated link|Dysentery}}
* {{annotated link|Fernando Mazariegos}}
* {{annotated link|Mucorrhea}}

== References ==
{{refs}}

== External links ==
{{Medical condition classification and resources
| DiseasesDB = 3742
| ICD10 = {{ICD10|A|09||a|00}}, {{ICD10|K|59|1|k|55}}
| ICD9 = {{ICD9|787.91}}
| ICDO =
| OMIM =
| MedlinePlus = 003126
| eMedicineSubj = ped
| eMedicineTopic = 583
| MeshID = D003967
}}
{{offline|med}}
{{Sister project links|display=Diarrhea|voy=no}}

* [https://www.who.int/news-room/fact-sheets/detail/diarrhoeal-disease WHO fact sheet on diarrhoeal disease]

{{Gastroenterology}}
{{Digestive system and abdomen symptoms and signs}}
{{Authority control}}

[[Category:Diarrhea| ]]
[[Category:Intestinal infectious diseases]]
[[Category:Waterborne diseases]]
[[Category:Diseases of intestines]]
[[Category:Conditions diagnosed by stool test]]
[[Category:Symptoms and signs: Digestive system and abdomen]]
[[Category:Feces]]
[[Category:Wikipedia medicine articles ready to translate]]
[[Category:Sanitation]]
[[Category:Wikipedia emergency medicine articles ready to translate]]
[[Category:Articles containing video clips]]