View source for Bowel obstruction

{{Short description|Mechanical or functional obstruction of the intestines}}
{{cs1 config|name-list-style=vanc|display-authors=6}}
{{Use mdy dates|date=February 2024}}
{{Infobox medical condition
| name          = Bowel obstruction
| image         = Upright X-ray demonstrating small bowel obstruction.jpg
| caption       = Upright [[abdominal X-ray]] demonstrating a small bowel obstruction. Note multiple air fluid levels.
| field         = [[General surgery]]
| synonyms      = Intestinal obstruction, intestinal occlusion
| symptoms      = [[Abdominal pain]], [[vomiting]], [[abdominal bloating|bloating]], not passing [[flatulence|gas]]<ref name=Gor2015/>
| complications = [[Sepsis]], bowel [[ischemia]], [[bowel perforation]]<ref name=Gor2015/>
| onset         =
| duration      =
| causes        = [[bowel adhesions|Adhesions]], [[hernia]]s, [[volvulus]], [[endometriosis]], [[inflammatory bowel disease]], [[appendicitis]], [[tumor]]s, [[diverticulitis]], [[ischemic colitis|ischemic bowel]], [[tuberculosis]], [[intussusception (medical disorder)|intussusception]]<ref name=SBO2010/><ref name=Gor2015/>
| risks         =
| diagnosis     = [[Medical imaging]]<ref name=Gor2015/>
| differential  =
| prevention    =
| treatment     = [[Conservative care]], [[surgery]]<ref name=SBO2010/>
| medication    =
| prognosis     =
| frequency     = 3.2 million (2015)<!— incidence —><ref name=GBD2015Pre/>
| deaths        = 238,733 (2019)<ref>{{Cite journal |last1=Long |first1=Dan |last2=Mao |first2=Chenhan |last3=Liu |first3=Yaxuan |last4=Zhou |first4=Tao |last5=Xu |first5=Yin |last6=Zhu |first6=Ying |date=2023-10-03 |title=Global, regional, and national burden of intestinal obstruction from 1990 to 2019: an analysis from the Global Burden of Disease Study 2019 |journal=International Journal of Colorectal Disease |language=en |volume=38 |issue=1 |page=245 |doi=10.1007/s00384-023-04522-6 |issn=1432-1262 |pmid=37787806 }}</ref>
}}

'''Bowel obstruction''', also known as '''intestinal obstruction''', is a mechanical or [[Ileus|functional obstruction]] of the [[Gastrointestinal tract#Lower gastrointestinal tract|intestine]]s that prevents the normal movement of the products of [[digestion]].<ref name="SBO2010">{{cite book |last=Fitzgerald |first=J. Edward F. |title=Emergency Surgery |publisher=[[Wiley-Blackwell]] |year=2010 |isbn=978-1-4051-7025-3 |location=Oxford |pages=74–79 |chapter=Small Bowel Obstruction |doi=10.1002/9781444315172.ch14 |chapter-url=https://books.google.com/books?id=iduO1gYydz0C&pg=PA74 |archive-url=https://web.archive.org/web/20170908221043/https://books.google.com/books?id=iduO1gYydz0C&pg=PA74 |archive-date=September 8, 2017 |url-status=live}}</ref><ref>{{cite book |last1=Adams |first1=James G. |url=https://books.google.com/books?id=rpoH-KYE93IC&pg=PA331 |title=Emergency Medicine: Clinical Essentials (Expert Consult -- Online) |date=2012 |publisher=Elsevier Health Sciences |isbn=978-1-4557-3394-1 |page=331 |language=en |archive-url=https://web.archive.org/web/20170908221043/https://books.google.com/books?id=rpoH-KYE93IC&pg=PA331 |archive-date=September 8, 2017 |url-status=live}}</ref> Either the [[Small intestine|small bowel]] or [[Large intestine|large bowel]] may be affected.<ref name="Gor2015">{{cite journal |vauthors=Gore RM, Silvers RI, Thakrar KH, Wenzke DR, Mehta UK, Newmark GM, Berlin JW |date=November 2015 |title=Bowel Obstruction |journal=Radiologic Clinics of North America |volume=53 |issue=6 |pages=1225–40 |doi=10.1016/j.rcl.2015.06.008 |pmid=26526435}}</ref> Signs and symptoms include [[abdominal pain]], [[vomiting]], [[abdominal bloating|bloating]] and not passing [[flatulence|gas]].<ref name=Gor2015/> Mechanical obstruction is the cause of about 5 to 15% of cases of [[acute abdomen|severe abdominal pain of sudden onset]] requiring admission to hospital.<ref name=Gor2015/><ref name=SBO2010/>

<!-- Cause and diagnosis -->
Causes of bowel obstruction include [[Adhesion (medicine)|adhesion]]s, [[hernia]]s, [[volvulus]], [[endometriosis]], [[inflammatory bowel disease]], [[appendicitis]], [[Neoplasm|tumor]]s, [[diverticulitis]], [[ischemic colitis|ischemic bowel]], [[tuberculosis]] and [[intussusception (medical disorder)|intussusception]].<ref name=Gor2015/><ref name=SBO2010/> Small bowel obstructions are most often due to adhesions and hernias while large bowel obstructions are most often due to tumors and volvulus.<ref name=Gor2015/><ref name=SBO2010/> The diagnosis may be made on plain [[X-ray]]s; however, [[CT scan]] is more accurate.<ref name=Gor2015/> [[Ultrasound]] or [[Magnetic resonance imaging|MRI]] may help in the diagnosis of children or [[Pregnancy|pregnant]] women.<ref name=Gor2015/>

<!-- Prevention and treatment -->
The condition may be treated conservatively or with [[surgery]].<ref name=SBO2010/> Typically [[Intravenous therapy|intravenous fluids]] are given, a [[Nasogastric intubation|nasogastric (NG) tube is placed through the nose into the stomach]] to decompress the intestines, and [[analgesics|pain medications]] are given.<ref name=SBO2010/> [[Antibiotic]]s are often given.<ref name=SBO2010/> In small bowel obstruction about 25% require surgery.<ref name=Fer2014/> Complications may include [[sepsis]], bowel [[ischemia]] and [[bowel perforation]].<ref name=Gor2015/>

<!-- Epidemiology -->
About 3.2 million cases of bowel obstruction occurred in 2015, which resulted in 264,000 deaths.<ref name="GBD2015Pre">{{cite journal |last1=Vos |first1=Theo |last2=Allen |first2=Christine |last3=Arora |first3=Megha |last4=Barber |first4=Ryan M. |last5=Bhutta |first5=Zulfiqar A. |last6=Brown |first6=Alexandria |last7=Carter |first7=Austin |last8=Casey |first8=Daniel C. |last9=Charlson |first9=Fiona J. |last10=Chen |first10=Alan Z. |last11=Coggeshall |first11=Megan |last12=Cornaby |first12=Leslie |last13=Dandona |first13=Lalit |last14=Dicker |first14=Daniel J. |last15=Dilegge |first15=Tina |date=October 2016 |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 |doi=10.1016/S0140-6736(16)31678-6 |pmc=5055577 |pmid=27733282 |last16=Erskine |first16=Holly E. |last17=Ferrari |first17=Alize J. |last18=Fitzmaurice |first18=Christina |last19=Fleming |first19=Tom |last20=Forouzanfar |first20=Mohammad H. |last21=Fullman |first21=Nancy |last22=Gething |first22=Peter W. |last23=Goldberg |first23=Ellen M. |last24=Graetz |first24=Nicholas |last25=Haagsma |first25=Juanita A. |last26=Hay |first26=Simon I. |last27=Johnson |first27=Catherine O. |last28=Kassebaum |first28=Nicholas J. |last29=Kawashima |first29=Toana |last30=Kemmer |first30=Laura}}</ref><ref name="GBD2015De">{{cite journal |last1=Wang |first1=Haidong |last2=Naghavi |first2=Mohsen |last3=Allen |first3=Christine |last4=Barber |first4=Ryan M. |last5=Bhutta |first5=Zulfiqar A. |last6=Carter |first6=Austin |last7=Casey |first7=Daniel C. |last8=Charlson |first8=Fiona J. |last9=Chen |first9=Alan Zian |last10=Coates |first10=Matthew M. |last11=Coggeshall |first11=Megan |last12=Dandona |first12=Lalit |last13=Dicker |first13=Daniel J. |last14=Erskine |first14=Holly E. |last15=Ferrari |first15=Alize J. |date=October 2016 |title=Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015 |journal=Lancet |volume=388 |issue=10053 |pages=1459–1544 |doi=10.1016/s0140-6736(16)31012-1 |pmc=5388903 |pmid=27733281 |last16=Fitzmaurice |first16=Christina |last17=Foreman |first17=Kyle |last18=Forouzanfar |first18=Mohammad H. |last19=Fraser |first19=Maya S. |last20=Fullman |first20=Nancy |last21=Gething |first21=Peter W. |last22=Goldberg |first22=Ellen M. |last23=Graetz |first23=Nicholas |last24=Haagsma |first24=Juanita A. |last25=Hay |first25=Simon I. |last26=Huynh |first26=Chantal |last27=Johnson |first27=Catherine O. |last28=Kassebaum |first28=Nicholas J. |last29=Kinfu |first29=Yohannes |last30=Kulikoff |first30=Xie Rachel}}</ref> Both sexes are equally affected and the condition can occur at any age.<ref name="Fer2014">{{cite book |last1=Ferri |first1=Fred F. |url=https://books.google.com/books?id=icTsAwAAQBAJ&pg=PA1093 |title=Ferri's Clinical Advisor 2015: 5 Books in 1 |date=2014 |publisher=Elsevier Health Sciences |isbn=978-0-323-08430-7 |page=1093 |language=en |archive-url=https://web.archive.org/web/20170908221043/https://books.google.com/books?id=icTsAwAAQBAJ&pg=PA1093 |archive-date=September 8, 2017 |url-status=live}}</ref> Bowel obstruction has been documented throughout history, with cases detailed in the [[Ebers Papyrus]] of 1550 BC and by [[Hippocrates]].<ref>{{cite book |last1=Yeo |first1=Charles J. |url=https://books.google.com/books?id=VTE-h2D1SNEC&pg=PA1851 |title=Shackelford's Surgery of the Alimentary Tract |last2=McFadden |first2=David W. |last3=Pemberton |first3=John H. |last4=Peters |first4=Jeffrey H. |last5=Matthews |first5=Jeffrey B. |date=2012 |publisher=Elsevier Health Sciences |isbn=978-1-4557-3807-6 |page=1851 |language=en |archive-url=https://web.archive.org/web/20170908221043/https://books.google.com/books?id=VTE-h2D1SNEC&pg=PA1851 |archive-date=September 8, 2017 |url-status=live}}</ref>
{{TOC limit|3}}

==Signs and symptoms==
Depending on the level of obstruction, bowel obstruction can present with [[abdominal pain]], [[abdominal distension]], and [[constipation]]. Bowel obstruction may be complicated by [[dehydration]] and [[electrolyte abnormalities]] due to vomiting; respiratory compromise from pressure on the [[diaphragm (anatomy)|diaphragm]] by a distended abdomen, or [[Pulmonary aspiration|aspiration]] of vomitus; bowel [[ischemia]] or [[Gastrointestinal perforation|perforation]] from prolonged distension or pressure from a foreign body and subsequently [[sepsis]] due to [[Gut microbiota|bowel flora]].<ref name="auto2">{{cite web |title=Large Bowel Obstruction |url=https://www.lecturio.com/concepts/large-bowel-obstruction/ |access-date=July 10, 2021 |website=The Lecturio Medical Concept Library}}</ref>{{listen
| filename    = SBOOgg louder.ogg
| title       = Tinkly bowel sounds
| description = Tinkly bowel sounds as heard with a [[stethoscope]] in someone with a small bowel obstruction.
| format      = [[Ogg]]
}}
In small bowel obstruction, the [[pain]] tends to be colicky (cramping and intermittent) in nature, with spasms lasting a few minutes. The pain tends to be central and mid-abdominal. Vomiting may occur before constipation.<ref name="auto2"/> Common physical exam findings may include signs of [[dehydration]], abdominal distension with tympany, nonspecific abdominal tenderness, and high pitched tinkly bowel sounds.<ref name=":0">{{Cite book |last1=Vercruysse |first1=Gary |url=https://www.ncbi.nlm.nih.gov/books/NBK572336/ |title=Evaluation and Management of Mechanical Small Bowel Obstruction in Adults |last2=Busch |first2=Rebecca |last3=Dimcheff |first3=Derek |last4=Al-Hawary |first4=Mahmoud |last5=Saad |first5=Richard |last6=Seagull |first6=F. Jacob |last7=Somand |first7=David |last8=Cherry-Bukowiec |first8=Jill |last9=Wanacata |first9=Lauren |date=2021 |publisher=Michigan Medicine University of Michigan |series=Michigan Medicine Clinical Care Guidelines |location=Ann Arbor (MI) |pmid=34314126}}</ref>

In large bowel obstruction, the pain is felt lower in the abdomen and the spasms last longer. Common symptoms include abdominal pain, distension, and severe constipation.<ref>{{Cite book |last=Ferri |first=Fred |title=Ferri's Clinical Advisor 2024 |date=July 12, 2023 |publisher=Elsevier |isbn=978-0-323-75576-4 |edition=1st |pages=829.e4–829.e6}}</ref> Constipation occurs earlier and vomiting may be less prominent. Proximal obstruction of the large bowel may present as small bowel obstruction.<ref name="auto2"/> Patients may notice a history of bloating and narrowing of stools before the onset of more severe symptoms. Symptoms can present quickly in the cases of [[volvulus]] and can present over a longer period of time in the setting of cancer. Common physical exam findings may include a palpable [[hernia]], abdominal distension with tympany, nonspecific lower abdominal tenderness, and a rectal mass.<ref name="Fer2014" />

==Causes==

===Small bowel obstruction===
[[File:Upright abdominal X-ray demonstrating a bowel obstruction.jpg|thumb|upright|Upright abdominal X-ray demonstrating a small bowel obstruction. Note multiple air fluid levels.]]
Causes of [[small bowel]] obstruction include:<ref name=SBO2010/>
* [[Adhesion (medicine)|Adhesions]] from previous abdominal surgery (most common cause)
* [[Barbed suture]]s<ref name="Segura">{{cite journal |vauthors=Segura-Sampedro JJ, Ashrafian H, Navarro-Sánchez A, Jenkins JT, Morales-Conde S, Martínez-Isla A |date=November 2015 |title=Small bowel obstruction due to laparoscopic barbed sutures: an unknown complication? |url=http://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S1130-01082015001100005 |journal=Revista Española de Enfermedades Digestivas |volume=107 |issue=11 |pages=677–80 |doi=10.17235/reed.2015.3863/2015 |hdl=20.500.13003/12378 |pmid=26541657 |doi-access=free |hdl-access=free}}</ref>
* [[Intestinal pseudoobstruction|Pseudoobstruction]]
* [[Hernia]]s containing bowel
* [[Crohn's disease]] causing adhesions or inflammatory strictures
* [[Neoplasia|Neoplasms]], benign or malignant
* [[Intussusception (medical disorder)|Intussusception]]
* [[Volvulus]]
* [[Superior mesenteric artery syndrome]], a compression of the [[duodenum]] by the [[superior mesenteric artery]] and the [[abdominal aorta]]
* [[Ischemic]] strictures
* [[Foreign bodies]] (e.g. [[gallstone]]s in [[gallstone ileus]], swallowed objects such as [[expandable water toy]]s)
* [[Intestinal atresia]]
* [[Urinary retention]]

After abdominal surgery, the incidence of small bowel obstruction from any cause is 9%. In those where the cause of the obstruction was clear, adhesions are the single most common cause (more than half).<ref name="auto">{{cite journal |vauthors=ten Broek RP, Issa Y, van Santbrink EJ, Bouvy ND, Kruitwagen RF, Jeekel J, Bakkum EA, Rovers MM, van Goor H |date=October 2013 |title=Burden of adhesions in abdominal and pelvic surgery: systematic review and met-analysis |journal=BMJ |volume=347 |issue=oct03 1 |article-number=f5588 |doi=10.1136/bmj.f5588 |pmc=3789584 |pmid=24092941}}</ref>

===Large bowel obstruction===
[[File:LargeBowelObsUp2008.jpg|thumb|upright|Upright abdominal X-ray of a person with a large bowel obstruction showing multiple air fluid levels and dilated loops of bowel]]
Causes of large bowel obstruction include:<ref name="auto1">{{cite web |title=Intestinal obstruction and Ileus |url=https://medlineplus.gov/ency/article/000260.htm |access-date=July 10, 2021 |website=MedlinePlus}}</ref>
* [[Neoplasm]]s / cancer
* [[Diverticulitis]] / [[Diverticulosis]]
* [[Hernia]]s
* [[Inflammatory bowel disease]]
* Colonic [[volvulus]] (sigmoid, caecal, transverse colon)
* [[Adhesion (medicine)|Adhesion]]s
* [[Constipation]]
* [[Fecal impaction]]
* [[Fecaloma]]
* [[Intestinal atresia|Colon atresia]]
* [[Intestinal pseudoobstruction]]
* [[Endometriosis]]
* Narcotic induced (especially with the large doses given to cancer or palliative care patients)

====Outlet obstruction====
Outlet obstruction is a sub-type of large bowel obstruction and refers to conditions affecting the anorectal region that obstruct [[defecation]], specifically conditions of the pelvic floor and anal sphincters. Outlet obstruction can be classified into four groups.<ref name="The Surgical Management of Evacutory Dysfunction">{{cite book |last1=Zbar |first1=Andrew P |title=Coloproctology |last2=Wexner |first2=Steven D |publisher=Springer |year=2010 |isbn=978-1-84882-755-4 |location=New York |page=140}}</ref>
* Functional outlet obstruction
** Inefficient inhibition of the internal anal sphincter
*** Short-segment [[Hirschsprung's disease]]
*** [[Chagas disease]]
*** Hereditary internal sphincter myopathy
** Inefficient relaxation of the striated pelvic floor muscles
*** [[Anismus]] (pelvic floor dyssynergia)
*** [[Multiple sclerosis]]
*** [[Spinal cord]] lesions
* Mechanical outlet obstruction
** [[Internal intussusception]]
** [[Enterocele]]
* Dissipation of force vector
** [[rectocele]]
** [[Descending perineum]]
** [[Rectal prolapse]]
* Impaired rectal sensitivity
** [[Megarectum]]
** Rectal hyposensitivity

==Diagnosis==
{| class="wikitable floatleft"
|+ Small bowel dilation on CT scan in adults<ref name="JacobsRozenblit2007">{{cite journal |vauthors=Jacobs SL, Rozenblit A, Ricci Z, Roberts J, Milikow D, Chernyak V, Wolf E |date=April 2007 |title=Small bowel faeces sign in patients without small bowel obstruction |journal=Clinical Radiology |volume=62 |issue=4 |pages=353–7 |doi=10.1016/j.crad.2006.11.007 |pmid=17331829}}</ref>
! Diameter !! Assessment
|-
| <2.5&nbsp;cm || Non-dilated
|-
| 2.5-2.9&nbsp;cm || Mildly dilated
|-
| 3–4&nbsp;cm || Moderately dilated
|-
| >4&nbsp;cm || Severely dilated
|}
[[File:PSBOCT.png|thumb|A small bowel obstruction as seen on CT]]
[[File:Diameters of the large intestine.svg|thumb|Average inner diameters and ranges of different sections of the large intestine.<ref name="Nguyen">{{cite journal |vauthors=Nguyen H, Loustaunau C, Facista A, Ramsey L, Hassounah N, Taylor H, Krouse R, Payne CM, Tsikitis VL, Goldschmid S, Banerjee B, Perini RF, Bernstein C |date=July 2010 |title=Deficient Pms2, ERCC1, Ku86, CcOI in field defects during progression to colon cancer |journal=Journal of Visualized Experiments |issue=41 |doi=10.3791/1931 |pmc=3149991 |pmid=20689513}}</ref>]]

The main diagnostic tools are [[blood test]]s, [[X-ray]]s of the abdomen, CT scanning, and [[medical ultrasonography|ultrasound]]. If a mass is identified, [[biopsy]] may determine the nature of the mass.{{citation needed|date=May 2022}}

[[Radiology|Radiological]] signs of bowel obstruction include bowel distension (small bowel loops dilated >3&nbsp;cm) and the presence of multiple (more than 2) air-fluid levels on supine and erect abdominal [[radiographs]].<ref>{{Citation |last1=Singh |first1=Ajay |title=Imaging of Bowel Obstruction |date=2018 |work=Emergency Radiology |pages=67–75 |editor-last=Singh |editor-first=Ajay |url=http://link.springer.com/10.1007/978-3-319-65397-6_5 |access-date=February 19, 2024 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-65397-6_5 |isbn=978-3-319-65396-9 |last2=Mansouri |first2=Mohammad |url-access=subscription}}</ref> Ultrasounds may be as useful as CT scanning to make the diagnosis.<ref>{{cite journal |vauthors=Gottlieb M, Peksa GD, Pandurangadu AV, Nakitende D, Takhar S, Seethala RR |date=February 2018 |title=Utilization of ultrasound for the evaluation of small bowel obstruction: A systematic review and meta-analysis |journal=The American Journal of Emergency Medicine |volume=36 |issue=2 |pages=234–242 |doi=10.1016/j.ajem.2017.07.085 |pmid=28797559 |s2cid=24769945}}</ref>

[[Enema|Contrast enema]] or small bowel series or CT scan can be used to define the level of obstruction, whether the obstruction is partial or complete, and to help define the cause of the obstruction. The appearance of water-soluble contrast in the cecum on an abdominal radiograph within 24 hours of it being given by mouth predicts resolution of an adhesive small bowel obstruction with [[sensitivity (tests)|sensitivity]] of 97% and [[specificity (tests)|specificity]] of 96%.<ref>{{cite journal |vauthors=Abbas S, Bissett IP, Parry BR |date=July 2007 |title=Oral water soluble contrast for the management of adhesive small bowel obstruction |journal=The Cochrane Database of Systematic Reviews |volume=2010 |issue=3 |article-number=CD004651 |doi=10.1002/14651858.CD004651.pub3 |pmc=6465054 |pmid=17636770}}</ref>

[[Colonoscopy]], small bowel investigation with ingested camera or push [[endoscopy]], and [[laparoscopy]] are other diagnostic options.

<gallery>
File:UOTW 20 - Ultrasound of the Week 1.webm|Small bowel obstruction on ultrasound<ref name="UOTW20">{{cite web |date=1 October 2014 |title=UOTW #20 - Ultrasound of the Week |url=https://www.ultrasoundoftheweek.com/uotw-20/ |url-status=live |archive-url=https://web.archive.org/web/20170509081636/https://www.ultrasoundoftheweek.com/uotw-20/ |archive-date=May 9, 2017 |access-date=27 May 2017 |website=Ultrasound of the Week }}</ref>
File:UOTW 20 - Ultrasound of the Week 2.webm|Small bowel obstruction on ultrasound<ref name="UOTW20" />
File:UOTW 20 - Ultrasound of the Week 3.jpg|Small bowel obstruction on ultrasound<ref name="UOTW20" />
</gallery>

===Differential diagnosis===
[[Differential diagnosis|Differential diagnoses]] of bowel obstruction include:
* [[Ileus]]
* [[Pseudo-obstruction]] or [[Ogilvie's syndrome]]
* Intra-abdominal [[sepsis]]
* [[Pneumonia]] or other systemic illness<ref name="auto3">{{cite web |title=Small Bowel Obstruction |url=https://www.lecturio.com/concepts/small-bowel-obstruction/ |access-date=July 10, 2021 |website=The Lecturio Medical Concept Library}}</ref>

==Treatment==
Treatment of small and large bowel obstructions are initially similar and non-operative management is usually the initial management strategy as the majority of small bowel obstruction resolve spontaneously with non-operative management.<ref name=":0"/><ref name=":1">{{Cite book |last=Ferri |first=Fred |title=Ferri's Clinical Advisor 2024 |date=July 12, 2023 |publisher=Elsevier |isbn=978-0-323-75576-4 |edition=1st}}</ref> Patients are monitored by the surgical team for signs of improvement and resolution of the obstruction on imaging; if the obstruction does not clear then surgical management for the treatment of the causative lesion is required.<ref>{{Cite journal |last1=Bower |first1=Katie Love |last2=Lollar |first2=Daniel I. |last3=Williams |first3=Sharon L. |last4=Adkins |first4=Farrell C. |last5=Luyimbazi |first5=David T. |last6=Bower |first6=Curtis E. |date=October 1, 2018 |title=Small Bowel Obstruction |url=https://www.sciencedirect.com/science/article/pii/S0039610918300719 |journal=Surgical Clinics of North America |series=Emergency General Surgery |volume=98 |issue=5 |pages=945–971 |doi=10.1016/j.suc.2018.05.007 |issn=0039-6109 |pmid=30243455 |s2cid=265759123 |url-access=subscription}}</ref> In malignant large bowel obstruction, endoscopically placed self-expanding metal [[stent]]s may be used to temporarily relieve the obstruction as a bridge to surgery,<ref>{{cite journal |vauthors=Young CJ, Suen MK, Young J, Solomon MJ |date=October 2011 |title=Stenting large bowel obstruction avoids a stoma: consecutive series of 100 patients |journal=Colorectal Disease |volume=13 |issue=10 |pages=1138–41 |doi=10.1111/j.1463-1318.2010.02432.x |pmid=20874797 |s2cid=12724976}}<!--| access-date =August 11, 2013 --></ref> or as [[Palliative care|palliation]].<ref>{{cite journal |vauthors=Mosler P, Mergener KD, Brandabur JJ, Schembre DB, Kozarek RA |date=February 2005 |title=Palliation of gastric outlet obstruction and proximal small bowel obstruction with self-expandable metal stents: a single center series |journal=Journal of Clinical Gastroenterology |volume=39 |issue=2 |pages=124–8 |pmid=15681907}}<!--| access-date =August 11, 2013 --></ref> Diagnosis of the type of bowel obstruction is normally conducted through initial plain [[Radiography|radiograph]] of the abdomen, luminal contrast studies, [[X-ray computed tomography|computed tomography scan]], or [[Medical ultrasonography|ultrasonography]] prior to determining the best type of treatment.<ref>{{cite book |last=Holzheimer |first=Rene G. |url=https://www.ncbi.nlm.nih.gov/books/NBK6880/ |title=Surgical Treatment |publisher=NCBI Bookshelf |year=2001 |isbn=3-88603-714-2 |archive-url=https://web.archive.org/web/20110827075739/http://www.ncbi.nlm.nih.gov/books/NBK6880/ |archive-date=August 27, 2011 |url-status=live }}</ref>

Further research is needed to find out if parenteral nutrition is of benefit to people with an inoperable blockage of the bowel caused by advanced cancer.<ref>{{cite journal |vauthors=Sowerbutts AM, Lal S, Sremanakova J, Clamp A, Todd C, Jayson GC, Teubner A, Raftery AM, Sutton EJ, Hardy L, Burden S |date=August 2018 |title=Home parenteral nutrition for people with inoperable malignant bowel obstruction |journal=The Cochrane Database of Systematic Reviews |volume=8 |issue=8 |article-number=CD012812 |doi=10.1002/14651858.cd012812.pub2 |pmc=6513201 |pmid=30095168}}</ref>

===Small bowel obstruction===
In the management of small bowel obstructions, a commonly quoted surgical aphorism is: "never let the sun rise or set on small-bowel obstruction"<ref name="Maglinte DD, Kelvin FM, Rowe MG, Bender GN, Rouch DM 39–46">{{cite journal |vauthors=Maglinte DD, Kelvin FM, Rowe MG, Bender GN, Rouch DM |date=January 2001 |title=Small-bowel obstruction: optimizing radiologic investigation and nonsurgical management |url=http://radiology.rsnajnls.org/cgi/content/full/218/1/39 |journal=Radiology |volume=218 |issue=1 |pages=39–46 |doi=10.1148/radiology.218.1.r01ja5439 |pmid=11152777 |url-access=subscription |archive-url=https://web.archive.org/web/20080418050916/http://radiology.rsnajnls.org/cgi/content/full/218/1/39 |archive-date=April 18, 2008 |access-date=June 6, 2008 }}</ref> because about 5.5%<ref name="Maglinte DD, Kelvin FM, Rowe MG, Bender GN, Rouch DM 39–46"/> of small bowel obstructions are ultimately fatal if treatment is delayed. Improvements in radiological imaging of small bowel obstructions allow for confident distinction between simple obstructions, that can be treated conservatively, and obstructions that are surgical emergencies ([[volvulus]], closed-loop obstructions, [[Ischemia#Bowel|ischemic bowel]], incarcerated [[hernia]]s, etc.).<ref name=SBO2010/> Exam findings of bowel compromise requiring immediate surgery include: severe abdominal pain, signs of [[peritonitis]] such as rebound tenderness, [[Tachycardia|elevated heart rate]], fever, and elevated inflammatory markers on lab work, such as [[Lactic acidosis|lactic acid]].<ref name=":0"/><ref name=":1"/>

A small flexible tube ([[nasogastric tube]]) may be inserted through the nose into the stomach to help decompress the dilated bowel. This tube is uncomfortable but relieves the abdominal cramps, distention, and vomiting. [[Intravenous therapy]] is utilized and the urine output may be monitored with a [[catheter]] in the [[urinary bladder|bladder]].<ref>[http://www.smallbowelobstruction.net/ Small Bowel Obstruction overview] {{webarchive|url=https://web.archive.org/web/20100212215648/http://smallbowelobstruction.net/ |date=February 12, 2010 }}. Retrieved February 19, 2010.</ref><ref name=":0"/>

Most people with SBO are initially managed conservatively because in many cases, the bowel will open up. Some adhesions loosen up and the obstruction resolves. The patient is examined several times a day, and [[X-ray imaging|X-ray images]] are made to ensure he or she is not getting clinically worse.<ref>[http://www.clearpassage.com/small-bowel-obstruction.php Small Bowel Obstruction:  Treating Bowel Adhesions Non-Surgically] {{webarchive|url=https://web.archive.org/web/20100227012047/http://www.clearpassage.com/small-bowel-obstruction.php |date=February 27, 2010 }}. ''Clear Passage treatment center online portal'' Retrieved February 19, 2010</ref>

Conservative treatment involves insertion of a [[nasogastric tube]], correction of dehydration and [[electrolyte]] abnormalities. [[Opioid]] pain relievers may be used for patients with severe pain but alternate pain relievers are preferred as opioids can decrease bowel motility.<ref name=":0"/>[[Antiemetics]] may be administered if the patient is vomiting. Adhesive obstructions often settle without surgery. If the obstruction is complete surgery is usually required.

Most patients improve with conservative care in 2–5 days. When the obstruction is cancer, surgery is the only treatment. Those with [[bowel resection]] or [[lysis]] of adhesions usually stay in the hospital a few more days until they can eat and walk.<ref>[http://www.east.org/tpg/sbo.pdf  Small Bowel Obstruction] {{webarchive|url=https://web.archive.org/web/20100705063225/http://www.east.org/tpg/sbo.pdf |date=July 5, 2010 }} The Eastern Association for the Surgery of Trauma. February 19, 2010</ref>

Small bowel obstruction caused by [[Crohn's disease]], peritoneal [[carcinomatosis]], sclerosing [[peritonitis]], [[radiation enteritis]], and postpartum bowel obstruction are typically treated conservatively, i.e. without surgery.

==Prognosis==
The prognosis for non-ischemic cases of SBO is good with mortality rates of 3–5%, while prognosis for SBO with ischemia is fair with mortality rates as high as 30%.<ref>{{cite conference |date=May 2006 |title=Mechanical Small Bowel Obstruction |url=http://eradiology.bidmc.harvard.edu/LearningLab/gastro/Kakoza.pdf |archive-url=https://web.archive.org/web/20130507080137/http://eradiology.bidmc.harvard.edu/LearningLab/gastro/Kakoza.pdf |archive-date=May 7, 2013 |access-date=October 9, 2012 |vauthors=Kakoza R, Lieberman G }}</ref>

Cases of SBO related to cancer are more complicated and require additional intervention to address the [[malignancy]], recurrence, and [[metastasis]], and thus are associated with a more poor prognosis.<ref name="auto3"/> Surgical options in patients with malignant bowel obstruction need to be considered carefully as while it may provide relief of symptoms in the short term, there is a high risk of mortality and re-obstruction.<ref>{{Cite journal |last1=Song |first1=Yun |last2=Metzger |first2=Daniel Aryeh |last3=Bruce |first3=Adrienne N. |last4=Krouse |first4=Robert S. |last5=Roses |first5=Robert E. |last6=Fraker |first6=Douglas L. |last7=Kelz |first7=Rachel R. |last8=Karakousis |first8=Giorgos C. |date=January 2022 |title=Surgical Outcomes in Patients With Malignant Small Bowel Obstruction: A National Cohort Study |url=https://journals.lww.com/10.1097/SLA.0000000000003890 |journal=Annals of Surgery |language=en |volume=275 |issue=1 |pages=e198–e205 |doi=10.1097/SLA.0000000000003890 |issn=0003-4932 |pmid=32209901 |s2cid=214643950 |url-access=subscription}}</ref>

All cases of abdominal surgical intervention are associated with increased risk of future small-bowel obstructions. Statistics from U.S. healthcare report 18.1% re-admittance rate within 30 days for patients who undergo SBO surgery.<ref name="SB154">{{cite news |date=April 2013 |title=Readmissions to U.S. Hospitals by Procedure |url=http://www.hcup-us.ahrq.gov/reports/statbriefs/sb154.pdf |url-status=live |archive-url=https://web.archive.org/web/20131020102447/http://www.hcup-us.ahrq.gov/reports/statbriefs/sb154.pdf |archive-date=October 20, 2013 |access-date=August 27, 2013 |newspaper=Agency for Healthcare Research and Quality }}</ref> More than 90% of patients also form adhesions after major abdominal surgery.<ref name="LiakokosPAE">{{cite journal |vauthors=Liakakos T, Thomakos N, Fine PM, Dervenis C, Young RL |year=2001 |title=Peritoneal adhesions: etiology, pathophysiology, and clinical significance. Recent advances in prevention and management |journal=Digestive Surgery |volume=18 |issue=4 |pages=260–73 |doi=10.1159/000050149 |pmid=11528133 |s2cid=30816909}}<!--| access-date =August 27, 2013 --></ref>
Common consequences of these adhesions include small-bowel obstruction, chronic abdominal pain, pelvic pain, and infertility.<ref name="LiakokosPAE"/>

==See also==
* {{Annotated link|Impaction (animals)}}
* {{Annotated link|Neonatal bowel obstruction}}
* [[Spastic intestinal obstruction]]

== References ==
{{Reflist}}

== External links ==
* {{eMedicine|emerg|66|Obstruction, Small Bowel}}
* {{eMedicine|emerg|65|Obstruction, Large Bowel}}
{{Medical condition classification and resources
| ICD10          = {{ICD10|K|56||k|55}}
| ICD9           = {{ICD9|560}}
| ICDO           =
| OMIM           =
| MedlinePlus    = 000260
| eMedicineSubj  =
| eMedicineTopic =
| DiseasesDB     = 15838
| MeshID         = D007415
}}
{{Gastroenterology}}

[[Category:Gastrointestinal tract disorders]]
[[Category:General surgery]]
[[Category:Medical emergencies]]
[[Category:Wikipedia emergency medicine articles ready to translate]]
[[Category:Wikipedia medicine articles ready to translate]]