View source for Colonoscopy

{{Short description|Examination of the bowel}}
{{Distinguish|colostomy}}
{{Use dmy dates|date=April 2025}}
{{cs1 config |name-list-style=vanc |display-authors=6}}
{{Infobox medical intervention
| Name        = Colonoscopy
| Image       = US Navy 110405-N-KA543-028 Hospitalman Urian D. Thompson, left, Lt. Cmdr. Eric A. Lavery and Registered Nurse Steven Cherry review the monitor whil.jpg
| Caption     = Colonoscopy being performed
| ICD10       =
| ICD9        = {{ICD9proc|45.23}}
| MeshID      = D003113
| OPS301      = {{OPS301|1-650}}
| MedlinePlus = 003886
| OtherCodes  =
}}

'''Colonoscopy''' ({{IPAc-en|ˌ|k|ɒ|l|ə|ˈ|n|ɒ|s|k|ə|p|i}}) or '''coloscopy''' ({{IPAc-en|k|ə|ˈ|l|ɒ|s|k|ə|p|i}})<ref>{{cite web | title = Colonoscopy | url = http://medical-dictionary.thefreedictionary.com/colonoscopy | work = The American Heritage Medical Dictionary | publisher = Houghton Mifflin Company | via = TheFreeDictionary | access-date = 28 October 2012 | archive-date = 12 May 2021 | archive-url = https://web.archive.org/web/20210512192101/https://medical-dictionary.thefreedictionary.com/colonoscopy | url-status = live }}</ref> is a medical procedure involving the [[Endoscopy|endoscopic]] examination of the [[large bowel]] (colon) and the [[distal]] portion of the small bowel. This examination is performed using either a [[Charge-coupled device|CCD camera]] or a [[fiber optic camera]], which is mounted on a flexible tube and passed through the anus.<ref name="uspstf">{{cite web |title=Recommendation: Colorectal Cancer: Screening | date=18 May 2021 |url=https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening |access-date=10 November 2023 |website=United States Preventive Services Task Force |archive-date=10 November 2023 |archive-url=https://web.archive.org/web/20231110015751/https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/colorectal-cancer-screening |url-status=live }}</ref><ref>{{cite web |title=Colonoscopy - NIDDK |url=https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy |access-date=10 November 2023 |website=National Institute of Diabetes and Digestive and Kidney Diseases |archive-date=3 May 2022 |archive-url=https://web.archive.org/web/20220503214437/https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy |url-status=live }}</ref>

The purpose of a colonoscopy is to provide a visual diagnosis via inspection of the internal lining of the colon wall, which may include identifying issues such as ulceration or [[Precancerous condition|precancerous]] polyps, and to enable the opportunity for [[biopsy]] or the removal of suspected [[colorectal cancer]] lesions.<ref>{{cite web |vauthors=Orr L |title=Do Colonoscopies Prevent Colon Cancer? |url=https://www.urmc.rochester.edu/news/story/do-colonoscopies-prevent-colon-cancer |access-date=7 November 2023 |website=URMC Newsroom |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107143401/https://www.urmc.rochester.edu/news/story/do-colonoscopies-prevent-colon-cancer |url-status=live }}</ref><ref>{{cite book |last1=Waye |first1=Jerome D. |url=https://onlinelibrary.wiley.com/doi/book/10.1002/9781118553442 |title=Practical Colonoscopy |last2=Aisenberg |first2=James |last3=Rubin |first3=Peter H. |date=18 April 2013 |publisher=Wiley |isbn=978-0-470-67058-3 |edition=1 |doi=10.1002/9781118553442 |access-date=10 November 2023 |archive-date=10 November 2023 |archive-url=https://web.archive.org/web/20231110042057/https://onlinelibrary.wiley.com/doi/book/10.1002/9781118553442 |url-status=live }}</ref>

Colonoscopy is similar to [[sigmoidoscopy]], but surveys the entire colon rather than only the sigmoid colon. A colonoscopy permits a comprehensive examination of the entire colon, which is typically around 1,200 to 1,500 millimeters in length.<ref>{{cite web |title=Small & Large Intestine Whereas a sigmoidoscopy is purposefully examining only the distal (left) side of the colon. |url=https://training.seer.cancer.gov/anatomy/digestive/regions/intestine.html |access-date=7 November 2023 |website=SEER Training |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107143404/https://training.seer.cancer.gov/anatomy/digestive/regions/intestine.html |url-status=live }}</ref>{{failed verification|date=April 2025}}

In contrast, a sigmoidoscopy allows for the examination of only the distal portion of the colon, which spans approximately 600 millimeters.<ref>{{cite web |title=Flexible sigmoidoscopy |url=https://www.cancerresearchuk.org/about-cancer/bowel-cancer/getting-diagnosed/tests/flexible-sigmoidoscopy |access-date=10 November 2023 |website=www.cancerresearchuk.org |archive-date=10 November 2023 |archive-url=https://web.archive.org/web/20231110045737/https://www.cancerresearchuk.org/about-cancer/bowel-cancer/getting-diagnosed/tests/flexible-sigmoidoscopy |url-status=live }}</ref>{{better source needed|date=April 2025}} This distinction is medically significant because the benefits of colonoscopy in terms of improving cancer survival have primarily been associated with the detection of lesions in the distal portion of the colon.<ref name="uspstf" />{{Request quotation|date=June 2025|reason = It's unclear where in the page this information is coming from.  Please provide quotation or indicate a specific, locatable section in the page.}}

Routine use of colonoscopy screening varies globally. In the US, colonoscopy is a commonly recommended and widely utilized screening method for colorectal cancer, often beginning at age 45 or 50, depending on risk factors and guidelines from organizations like the American Cancer Society.<ref name="colon-rectal-cancer">{{cite web |title=Colorectal Cancer Guideline |url=https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/acs-recommendations.html |access-date=7 November 2023 |website=www.cancer.org |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107000040/https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/acs-recommendations.html |url-status=live }}</ref> However, screening practices differ worldwide. For example, in the European Union, several countries primarily employ fecal occult blood testing (FOBT) or sigmoidoscopy for population-based screening.<ref>{{cite web |title=Statement on the Council cancer screening recommendations |url=https://www.feam.eu/statement-on-the-european-council-cancer-screening-recommendations/ |access-date=7 November 2023 |website=FEAM |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107161234/https://www.feam.eu/statement-on-the-european-council-cancer-screening-recommendations/ |url-status=live }}</ref> These variations stem from differences in healthcare systems, policies, and cultural factors. Recent studies<ref>{{cite journal | vauthors = Wong MC, Huang J, Liang PS | title = Is the practice of colorectal cancer screening questionable after the NordICC trial was published? | journal = Clinical and Translational Medicine | volume = 13 | issue = 10 | article-number = e1365 | date = October 2023 | pmid = 37792640 | pmc = 10550029 | doi = 10.1002/ctm2.1365 }}</ref> have stressed the need for screening strategies and awareness campaigns to combat colorectal cancer - on a global scale.<ref>{{cite journal | vauthors = Audibert C, Perlaky A, Glass D | title = Global perspective on colonoscopy use for colorectal cancer screening: A multi-country survey of practicing colonoscopists | journal = Contemporary Clinical Trials Communications | volume = 7 | pages = 116–121 | date = September 2017 | pmid = 29696175 | pmc = 5898517 | doi = 10.1016/j.conctc.2017.06.008 }}</ref><ref>{{cite journal | vauthors = Hayman CV, Vyas D | title = Screening colonoscopy: The present and the future | journal = World Journal of Gastroenterology | volume = 27 | issue = 3 | pages = 233–239 | date = January 2021 | pmid = 33519138 | pmc = 7814366 | doi = 10.3748/wjg.v27.i3.233 | doi-access = free }}</ref>

==Medical uses==
[[File:Diameters of the large intestine.svg|thumb|Inner diameters of colon sections]]
Conditions that call for colonoscopies include [[Gastrointestinal bleeding|gastrointestinal hemorrhage]], unexplained changes in bowel habit and suspicion of [[malignancy]].<ref>{{cite web |title=Colorectal Cancer Signs and Symptoms |url=https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/signs-and-symptoms.html |access-date=7 November 2023 |website=www.cancer.org |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107153325/https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/signs-and-symptoms.html |url-status=live }}</ref> Colonoscopies are often used to diagnose [[colon polyp]] and [[colon cancer]],<ref>{{cite web |title=Colonoscopy |url=https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy |website=[[National Institute of Diabetes and Digestive and Kidney Diseases]] |access-date=5 May 2022 |archive-date=3 May 2022 |archive-url=https://web.archive.org/web/20220503214437/https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopy |url-status=live }}</ref> but are also frequently used to diagnose [[inflammatory bowel disease]].<ref>{{cite web |title=Colonoscopy |url=https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/colonoscopy |publisher=[[Johns Hopkins School of Medicine]] |access-date=5 May 2022 |date=7 December 2021 |archive-date=5 May 2022 |archive-url=https://web.archive.org/web/20220505070700/https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/colonoscopy |url-status=live }}</ref><ref>{{cite journal | vauthors = Passos MA, Chaves FC, Chaves-Junior N | title = The Importance of Colonoscopy in Inflammatory Bowel Diseases | journal = Arquivos Brasileiros de Cirurgia Digestiva | volume = 31 | issue = 2 | article-number = e1374 | date = 2 July 2018 | pmid = 29972402 | pmc = 6044200 | doi = 10.1590/0102-672020180001e1374 }}</ref>

[[Fecal occult blood]] is a quick test which can be done to test for microscopic traces of blood in the stool. A positive test is almost always an indication to do a colonoscopy. In most cases the positive result is just due to [[hemorrhoids]]; however, it can also be due to [[diverticulosis]], inflammatory bowel disease ([[Crohn's disease]], [[ulcerative colitis]]), colon cancer, or [[polyp (medicine)|polyps]]. [[Colonic polypectomy]] has become a routine part of colonoscopy, allowing quick and simple removal of polyps during the procedure, without invasive surgery.<ref>{{cite journal | vauthors = Sivak MV | title = Polypectomy: looking back | journal = Gastrointestinal Endoscopy | volume = 60 | issue = 6 | pages = 977–982 | date = December 2004 | pmid = 15605015 | doi = 10.1016/S0016-5107(04)02380-6 }}</ref>

With regard to blood in the stool either visible or occult, it is worthy of note, that occasional rectal bleeding may have multiple non-serious potential causes.<ref>{{cite web |title=Rectal Bleeding: What It Means & When to Worry |url=https://my.clevelandclinic.org/health/symptoms/14612-rectal-bleeding |access-date=7 November 2023 |website=Cleveland Clinic |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107173758/https://my.clevelandclinic.org/health/symptoms/14612-rectal-bleeding |url-status=live }}</ref>

===Colon cancer screening===
Colonoscopy is one of the colorectal cancer screening tests available to people in the US who are 45 years of age and older. The other screening tests include [[flexible sigmoidoscopy]], [[double-contrast barium enema]], [[virtual colonoscopy|computed tomographic (CT) colonography]] (virtual colonoscopy), [[stool guaiac test|guaiac-based fecal occult blood test]] (gFOBT), [[fecal immunochemical test]] (FIT), and [[multitarget stool DNA screening test]] (Cologuard).<ref>{{cite web | title=Colorectal Cancer Prevention and Early Detection | url=http://www.cancer.org/acs/groups/cid/documents/webcontent/003170-pdf.pdf | pages=16–24 | publisher=[[American Cancer Society]] | date=5 February 2015 | access-date=25 December 2015 | archive-date=16 November 2015 | archive-url=https://web.archive.org/web/20151116102751/http://www.cancer.org/acs/groups/cid/documents/webcontent/003170-pdf.pdf }}</ref>

Subsequent rescreenings are then scheduled based on the initial results found, with a five- or ten-year recall being common for colonoscopies that produce normal results.<ref>{{cite journal | vauthors = Rex DK, Bond JH, Winawer S, Levin TR, Burt RW, Johnson DA, Kirk LM, Litlin S, Lieberman DA, Waye JD, Church J, Marshall JB, Riddell RH | title = Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the U.S. Multi-Society Task Force on Colorectal Cancer | journal = The American Journal of Gastroenterology | volume = 97 | issue = 6 | pages = 1296–1308 | date = June 2002 | pmid = 12094842 | doi = 10.1111/j.1572-0241.2002.05812.x | s2cid = 26250449 }}</ref><ref name = "pmid28555630">{{cite journal | vauthors = Rex DK, Boland CR, Dominitz JA, Giardiello FM, Johnson DA, Kaltenbach T, Levin TR, Lieberman D, Robertson DJ | title = Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer | journal = The American Journal of Gastroenterology | volume = 112 | issue = 7 | pages = 1016–1030 | date = July 2017 | pmid = 28555630 | doi = 10.1038/ajg.2017.174 | publisher = Ovid Technologies (Wolters Kluwer Health) | s2cid = 6808521 }}</ref>

Among people who have had an initial colonoscopy that found no polyps, the risk of developing colorectal cancer within five years is extremely low. Therefore, there is no need for those people to have another colonoscopy sooner than five years after the first screening.<ref>{{cite journal | vauthors = Imperiale TF, Glowinski EA, Lin-Cooper C, Larkin GN, Rogge JD, Ransohoff DF | title = Five-year risk of colorectal neoplasia after negative screening colonoscopy | journal = The New England Journal of Medicine | volume = 359 | issue = 12 | pages = 1218–1224 | date = September 2008 | pmid = 18799558 | doi = 10.1056/NEJMoa0803597 | doi-access = free }}</ref><ref>{{cite web | date = 2008-09-15 | title = No Need to Repeat Colonoscopy Until 5 Years After First Screening | url = https://www.newswise.com/articles/no-need-to-repeat-colonoscopy-until-5-years-after-first-screening | publisher = newswise, University of North Carolina Health Care System | archive-url = https://web.archive.org/web/20181216032223/https://www.newswise.com//articles/view/544318/ | archive-date = 2018-12-16 | url-status = live }}</ref>

Some medical societies in the US recommend a screening colonoscopy every ten years beginning at age 50 for adults without increased risk for colorectal cancer.<ref name="coloscreen">{{cite journal | vauthors = Winawer S, Fletcher R, Rex D, Bond J, Burt R, Ferrucci J, Ganiats T, Levin T, Woolf S, Johnson D, Kirk L, Litin S, Simmang C | title = Colorectal cancer screening and surveillance: clinical guidelines and rationale-Update based on new evidence | journal = Gastroenterology | volume = 124 | issue = 2 | pages = 544–560 | date = February 2003 | pmid = 12557158 | doi = 10.1053/gast.2003.50044 | doi-access = free }}</ref> Research shows that the risk of cancer is low for 10 years if a high-quality colonoscopy does not detect cancer, so tests for this purpose are indicated every ten years.<ref name="coloscreen"/><ref name="AGAfive">{{Citation|author1=American Gastroenterological Association |author1-link=American Gastroenterological Association |title=Five Things Physicians and Patients Should Question |publisher=[[American Gastroenterological Association]] |work=Choosing Wisely: an initiative of the [[ABIM Foundation]] |url=http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AGA.pdf |access-date=17 August 2012 |archive-url=https://web.archive.org/web/20120809143636/http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AGA.pdf |archive-date=9 August 2012 }}</ref>

Colonoscopy screening is associated with approximately two-thirds fewer deaths due to colorectal cancers on the left side of the colon, and is not associated with a significant reduction in deaths from right-sided disease. It is speculated that colonoscopy might reduce rates of death from colon cancer by detecting some colon polyps and cancers on the left side of the colon early enough that they may be treated, and a smaller number on the right side.<ref name="Baxter09">{{cite journal | vauthors = Baxter NN, Goldwasser MA, Paszat LF, Saskin R, Urbach DR, Rabeneck L | title = Association of colonoscopy and death from colorectal cancer | journal = Annals of Internal Medicine | volume = 150 | issue = 1 | pages = 1–8 | date = January 2009 | pmid = 19075198 | doi = 10.7326/0003-4819-150-1-200901060-00306 | doi-access = free | url = http://www.media.dssimon.com/taperequest/acp50_study.pdf | archive-url = https://web.archive.org/web/20120118213536/http://www.media.dssimon.com/taperequest/acp50_study.pdf | archive-date=18 January 2012 }}</ref>

Since polyps often take 10 to 15 years to transform into cancer in someone at average risk of colorectal cancer, guidelines recommend 10 years after a normal screening colonoscopy before the next colonoscopy. (This interval does not apply to people at high risk of colorectal cancer or those who experience symptoms of the disease.)<ref>{{cite web | work = Cancerconnect | url = http://news.cancerconnect.com/interval-between-colonoscopies-may-be-shorter-than-recommended/ | title = Interval between Colonoscopies May be Shorter than Recommended | date = 12 May 2011 | archive-url = https://web.archive.org/web/20110807154552/http://news.cancerconnect.com/interval-between-colonoscopies-may-be-shorter-than-recommended/ | archive-date=7 August 2011 | access-date = 2 June 2011 }}</ref><ref name="goodwin">{{cite journal | vauthors = Goodwin JS, Singh A, Reddy N, Riall TS, Kuo YF | title = Overuse of screening colonoscopy in the Medicare population | journal = Archives of Internal Medicine | volume = 171 | issue = 15 | pages = 1335–1343 | date = August 2011 | pmid = 21555653 | pmc = 3856662 | doi = 10.1001/archinternmed.2011.212 | url = http://archinte.ama-assn.org/cgi/content/short/archinternmed.2011.212 | access-date = 30 May 2011 | archive-url = https://web.archive.org/web/20110901031030/http://archinte.ama-assn.org/cgi/content/short/archinternmed.2011.212 | archive-date = 1 September 2011 }}</ref>

The large [[Randomized controlled trial|randomized]] [[pragmatic clinical trial]] NordICC was the first published trial on the use of colonoscopy as a screening test to prevent colorectal cancer, related death, and death from any cause. It included 84,585 healthy men and women aged 55 to 64 years in Poland, Norway, and Sweden, who were randomized to either receive an invitation to undergo a single screening colonoscopy (invited group) or to receive no invitation or screening (usual-care group). Of the 28,220 people in the invited group, 11,843 (42.0%) underwent screening. A total of 15 people who underwent colonoscopy (0.13%) had major bleeding after polyp removal.

None of the participants experienced a [[colon perforation]] due to colonoscopy. After 10 years, an [[Intention-to-treat analysis|intention-to-screen analysis]] showed a significant [[relative risk reduction]] of 18% in the risk of colorectal cancer (0.98% in the invited group vs. 1.20% in the usual-care group). The analysis showed no significant change in the risk of death from colorectal cancer (0.28% vs. 0.31%) or in the risk of death from any cause (11.03% vs. 11.04%). To prevent one case of colorectal cancer, 455 invitations to colonoscopy were required.<ref name="Bretthauer2022">{{cite journal | vauthors = Bretthauer M, Løberg M, Wieszczy P, Kalager M, Emilsson L, Garborg K, Rupinski M, Dekker E, Spaander M, Bugajski M, Holme Ø, Zauber AG, Pilonis ND, Mroz A, Kuipers EJ, Shi J, Hernán MA, Adami HO, Regula J, Hoff G, Kaminski MF | title = Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death | journal = The New England Journal of Medicine | volume = 387 | issue = 17 | pages = 1547–1556 | date = October 2022 | pmid = 36214590 | doi = 10.1056/NEJMoa2208375 | hdl-access = free | s2cid = 252778114 | hdl = 10852/101829 }}</ref><ref name="NordICC">{{ClinicalTrialsGov|NCT00883792|The Northern-European Initiative on Colorectal Cancer (NordICC)}}</ref>

As of 2023, the CONFIRM trial, a randomized trial evaluating colonoscopy vs. [[fecal immunochemical test]] is currently ongoing.<ref>{{cite web|url=https://clinicaltrials.gov/ct2/show/NCT01239082|title=Colonoscopy Versus Fecal Immunochemical Test in Reducing Mortality From Colorectal Cancer (CONFIRM) - Full Text View - ClinicalTrials.gov|website=clinicaltrials.gov|access-date=25 February 2019|archive-date=26 February 2019|archive-url=https://web.archive.org/web/20190226050032/https://clinicaltrials.gov/ct2/show/NCT01239082|url-status=live}}</ref>

In 2021, the US spent $43 billion on cancer screening to prevent five cancers, with colonoscopies accounting for 55% of the total.<ref>{{Cite journal |pmid=39102723 |date=2024 |last1=Halpern |first1=M. T. |last2=Liu |first2=B. |last3=Lowy |first3=D. R. |last4=Gupta |first4=S. |last5=Croswell |first5=J. M. |last6=Doria-Rose |first6=V. P. |title=The Annual Cost of Cancer Screening in the United States |journal=Annals of Internal Medicine |volume=177 |issue=9 |pages=1170–1178 |doi=10.7326/M24-0375 }}</ref> The death rate from colon cancer has been on a linear decline for 40 years, falling by nearly 50 percent from the 1980s (when few were screened) to 2024; however, the increase in screening did not accelerate the decline.<ref>{{cite news |last1=Kolata |first1=Gina |title=$43 Billion Price Tag on Cancer Screening Each Year Spurs Debate |url=https://www.nytimes.com/2024/08/05/health/cancer-screening-tests-cost.html |access-date=7 August 2024 |work=The New York Times |date=7 August 2024}}</ref> Therefore, resources devoted to cancer screening would be better directed toward ensuring widespread access to effective cancer treatment.<ref>{{Cite journal |pmid=39102720 |date=2024 |last1=Welch |first1=H. G. |title=Dollars and Sense: The Cost of Cancer Screening in the United States |journal=Annals of Internal Medicine |volume=177 |issue=9 |pages=1275–1276 |doi=10.7326/M24-0887 }}</ref>

===Recommendations===
The [[American Cancer Society]] issues recommendations on colorectal cancer screening guidelines. These guidelines often change and are updated as new studies and technologies have become available<ref name="colon-rectal-cancer"/>

Many other national organizations also issue such guidance, such as the UK's [[National Health Service|NHS]]<ref>{{cite web |title=Bowel cancer screening: guidelines for colonoscopy |url=https://www.gov.uk/government/publications/bowel-cancer-screening-colonoscopy-quality-assurance/bowel-cancer-screening-guidelines-for-colonoscopy |access-date=7 November 2023 |website=GOV.UK |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107204229/https://www.gov.uk/government/publications/bowel-cancer-screening-colonoscopy-quality-assurance/bowel-cancer-screening-guidelines-for-colonoscopy |url-status=live }}</ref> and various European agencies,<ref>{{cite journal | vauthors = Bénard F, Barkun AN, Martel M, von Renteln D | title = Systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations | journal = World Journal of Gastroenterology | volume = 24 | issue = 1 | pages = 124–138 | date = January 2018 | pmid = 29358889 | pmc = 5757117 | doi = 10.3748/wjg.v24.i1.124 | doi-access = free }}</ref> guidance can vary between such agencies.

===Medicare coverage===
In the United States, [[Medicare (United States)|Medicare]] insurance covers a number of colorectal-cancer screening tests.<ref>{{cite web |title=Colonoscopy Screening Coverage |url=https://www.medicare.gov/coverage/colonoscopies |access-date=7 November 2023 |website=www.medicare.gov |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107214504/https://www.medicare.gov/coverage/colonoscopies |url-status=live }}</ref>

==Procedural risks==
The American Society for Gastrointestinal Endoscopy estimates around three in 1,000 colonoscopies lead to serious complications.<ref>{{cite web |title=Are Colonoscopies Dangerous? |url=https://www.ccalliance.org/blog/prevention/are-colonoscopies-dangerous |access-date=7 November 2023 |website=Colorectal Cancer Alliance |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107212917/https://www.ccalliance.org/blog/prevention/are-colonoscopies-dangerous |url-status=live }}</ref>

===Perforation===
The most serious complication is generally [[gastrointestinal perforation]], which is life-threatening and requires immediate surgical intervention.<ref name=SartelliViale2013>{{cite journal | vauthors = Sartelli M, Viale P, Catena F, Ansaloni L, Moore E, Malangoni M, Moore FA, Velmahos G, Coimbra R, Ivatury R, Peitzman A, Koike K, Leppaniemi A, Biffl W, Burlew CC, Balogh ZJ, Boffard K, Bendinelli C, Gupta S, Kluger Y, Agresta F, Di Saverio S, Wani I, Escalona A, Ordonez C, Fraga GP, Junior GA, Bala M, Cui Y, Marwah S, Sakakushev B, Kong V, Naidoo N, Ahmed A, Abbas A, Guercioni G, Vettoretto N, Díaz-Nieto R, Gerych I, Tranà C, Faro MP, Yuan KC, Kok KY, Mefire AC, Lee JG, Hong SK, Ghnnam W, Siribumrungwong B, Sato N, Murata K, Irahara T, Coccolini F, Segovia Lohse HA, Verni A, Shoko T | title = 2013 WSES guidelines for management of intra-abdominal infections | journal = World Journal of Emergency Surgery | volume = 8 | issue = 1 | article-number = 3 | date = January 2013 | pmid = 23294512 | pmc = 3545734 | doi = 10.1186/1749-7922-8-3 | type = Review | doi-access = free }}</ref>

===Issues from general anesthesia===
As with any procedure involving [[anesthesia]], complications can occur, such as:<ref>{{cite web |title=Anesthesia Risk Assessment |url=https://www.asahq.org/madeforthismoment/anesthesia-101/types-of-anesthesia/anesthesia-risks/ |access-date=9 November 2023 |website=Made For This Moment |archive-date=9 November 2023 |archive-url=https://web.archive.org/web/20231109170043/https://www.asahq.org/madeforthismoment/anesthesia-101/types-of-anesthesia/anesthesia-risks/ |url-status=live }}</ref><ref>{{Citation |last1=Smith |first1=Guerin |title=General Anesthesia for Surgeons |date=2023 |url=https://www.ncbi.nlm.nih.gov/books/NBK493199/ |work=StatPearls |access-date=10 November 2023 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29630251 |last2=D'Cruz |first2=Jason R. |last3=Rondeau |first3=Bryan |last4=Goldman |first4=Julie |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326221442/https://www.ncbi.nlm.nih.gov/books/NBK493199/ |url-status=live }}</ref>
* allergic reactions,
* cardiovascular issues,
* paradoxical agitation,
* aspiration,
* dental injury.

===Colon preparation electrolyte issues===
Electrolyte imbalance caused by bowel preparation solutions is possible, but current bowel cleansing laxatives are formulated to account for electrolyte balance, making this a very rare event.<ref>{{cite journal | vauthors = Costelha J, Dias R, Teixeira C, Aragão I | title = Hyponatremic Coma after Bowel Preparation | journal = European Journal of Case Reports in Internal Medicine | volume = 6 | issue = 9 | page = 001217 | date = 26 August 2019 | pmid = 31583213 | pmc = 6774655 | doi = 10.12890/2019_001217 }}</ref>

===Other===
During colonoscopies, when a [[Polyp (medicine)|polyp]] is removed (a polypectomy), the risk of complication increases.<ref>{{cite journal |last1=Choo |first1=Wai Kah |last2=Subhani |first2=Javaid |date=2012 |title=Complication rates of colonic polypectomy in relation to polyp characteristics and techniques: a district hospital experience |journal=Journal of Interventional Gastroenterology |volume=2 |issue=1 |pages=8–11 |doi=10.4161/jig.20126 |issn=2154-1280 |pmc=3350902 |pmid=22586542}}</ref><ref>{{cite journal |last1=Tomaszewski |first1=Marcel |last2=Sanders |first2=David |last3=Enns |first3=Robert |last4=Gentile |first4=Laura |last5=Cowie |first5=Scott |last6=Nash |first6=Carla |last7=Petrunia |first7=Denis |last8=Mullins |first8=Paul |last9=Hamm |first9=Jeremy |last10=Azari-Razm |first10=Nazanin |last11=Bykov |first11=Dmitriy |last12=Telford |first12=Jennifer |date=12 October 2021 |title=Risks associated with colonoscopy in a population-based colon screening program: an observational cohort study |journal=CMAJ Open |volume=9 |issue=4 |pages=E940–E947 |doi=10.9778/cmajo.20200192 |doi-access=free |issn=2291-0026 |pmc=8513602 |pmid=34642256}}</ref> One of the most serious complications is [[postpolypectomy coagulation syndrome]], occurring in 1 in {{val|1000}} procedures.<ref>{{cite journal |last1=Jehangir |first1=Asad |last2=Bennett |first2=Kyle M. |last3=Rettew |first3=Andrew C. |last4=Fadahunsi |first4=Opeyemi |last5=Shaikh |first5=Bilal |last6=Donato |first6=Anthony |date=19 October 2015 |title=Post-polypectomy electrocoagulation syndrome: a rare cause of acute abdominal pain |journal=Journal of Community Hospital Internal Medicine Perspectives |volume=5 |issue=5 |article-number=10.3402/jchimp.v5.29147 |doi=10.3402/jchimp.v5.29147 |issn=2000-9666 |pmc=4612487 |pmid=26486121}}</ref> It results from a burn injury to the wall of the colon causing abdominal pain, fever, elevated white blood cell count and elevated serum [[C-reactive protein]]. Treatment consists of intravenous fluids, antibiotics, and avoiding oral intake of food, water, etc. until symptoms improve. Risk factors include right colon polypectomy, large polyp size (>2&nbsp;cm), non-polypoid lesions (laterally spreading lesions), and hypertension.<ref>{{cite journal | vauthors = Anderloni A, Jovani M, Hassan C, Repici A | title = Advances, problems, and complications of polypectomy | journal = Clinical and Experimental Gastroenterology | volume = 7 | pages = 285–296 | date = 30 August 2014 | pmid = 25210470 | pmc = 4155740 | doi = 10.2147/CEG.S43084 | doi-access = free }}</ref>

Although rare, infections of the colon are a potential colonoscopy risk. The colon is not a [[Sterilization (microbiology)|sterile]] environment, and infections can occur during biopsies from what is essentially a 'small shallow cut', enabling bacterial intrusion into lower parts of the colon wall. In cases where the lining of the colon is perforated, bacteria can infiltrate the [[abdominal cavity]].<ref name="CRisks">{{cite web |url=http://www.colonoscopyrisks.net/bowel-infection.php |title=Bowel Infections |access-date=6 April 2010 |archive-date=2 April 2019 |archive-url=https://web.archive.org/web/20190402163529/http://www.colonoscopyrisks.net/bowel-infection.php }}</ref>

Minor colonoscopy risks may include [[nausea]], [[vomiting]] or [[allergies]] to the [[sedatives]] that may have been used. If medication is given intravenously, the [[vein]] may become irritated, or mild [[phlebitis]] may occur.<ref name="MediNet">{{cite web |url=http://www.medicinenet.com/colonoscopy/page3.htm#8whatare |title=What to expect after a colonoscopy? |access-date=6 April 2010 |archive-date=9 August 2017 |archive-url=https://web.archive.org/web/20170809074136/http://www.medicinenet.com/colonoscopy/page3.htm#8whatare |url-status=live }}</ref>

==Technique==

===Preparation===
[[File:polyethylene glycol container.jpg|thumb|alt=A container of PEG (polyethylene glycol) with electrolyte used to clean out the intestines before certain bowel exam procedures such as colonoscopy.|A container of PEG ([[macrogol|polyethylene glycol or macrogol]]) with electrolyte used to clean out the [[intestines]] before certain [[bowel]] exam procedures such as a colonoscopy.]]

The colon must be free of solid matter for the test to be performed properly.<ref name="pmid25239068">{{cite journal | vauthors = Johnson DA, Barkun AN, Cohen LB, Dominitz JA, Kaltenbach T, Martel M, Robertson DJ, Boland CR, Giardello FM, Lieberman DA, Levin TR, Rex DK | title = Optimizing adequacy of bowel cleansing for colonoscopy: recommendations from the US multi-society task force on colorectal cancer | journal = Gastroenterology | volume = 147 | issue = 4 | pages = 903–924 | date = October 2014 | pmid = 25239068 | doi = 10.1053/j.gastro.2014.07.002 | publisher = Elsevier BV | doi-access = free }}</ref> For one to three days, the patient is required to follow a [[Low-fiber diet|low fiber]] or clear-liquid-only diet. Examples of clear fluids are [[apple juice]], chicken and/or beef broth or [[Bouillon (broth)|bouillon]], [[lemon-lime]] [[Soft drink|soda]], lemonade, [[sports drink]], and [[Drinking water|water]]. It is important that the patient remains hydrated. Sports drinks contain [[electrolyte]]s which are depleted during the purging of the bowel. Drinks containing fiber such as [[prune]] and [[orange juice]] should not be consumed, nor should liquids [[Food colouring|dyed]] red, purple, orange, or sometimes brown; however, cola is allowed. In most cases, [[tea]] or [[coffee]] taken without milk are allowed.<ref>{{cite web |title=Preparing for Your Colonoscopy: Types of Kits & Instructions |url=https://my.clevelandclinic.org/health/treatments/22657-colonoscopy-bowel-preparation |access-date=9 November 2023 |website=Cleveland Clinic |archive-date=9 November 2023 |archive-url=https://web.archive.org/web/20231109202335/https://my.clevelandclinic.org/health/treatments/22657-colonoscopy-bowel-preparation |url-status=live }}</ref><ref>{{cite journal | vauthors = Parra-Blanco A, Nicolas-Perez D, Gimeno-Garcia A, Grosso B, Jimenez A, Ortega J, Quintero E | title = The timing of bowel preparation before colonoscopy determines the quality of cleansing, and is a significant factor contributing to the detection of flat lesions: a randomized study | journal = World Journal of Gastroenterology | volume = 12 | issue = 38 | pages = 6161–6166 | date = October 2006 | pmid = 17036388 | pmc = 4088110 | doi = 10.3748/wjg.v12.i38.6161 | doi-access = free }}</ref>

The day before the colonoscopy (or [[colorectal surgery]]), the patient is either given a [[laxative]] preparation (such as [[bisacodyl]], [[phospho soda]], [[sodium picosulfate]], or [[sodium phosphate]] and/or [[magnesium citrate]]) and large quantities of fluid, or [[whole bowel irrigation]] is performed using a solution of [[polyethylene glycol]] and [[electrolytes]].<ref>{{cite journal | vauthors = Hung SY, Chen HC, Chen WT | title = A Randomized Trial Comparing the Bowel Cleansing Efficacy of Sodium Picosulfate/Magnesium Citrate and Polyethylene Glycol/Bisacodyl (The Bowklean Study) | journal = Scientific Reports | volume = 10 | issue = 1 | article-number = 5604 | date = March 2020 | pmid = 32221332 | pmc = 7101403 | doi = 10.1038/s41598-020-62120-w | bibcode = 2020NatSR..10.5604H }}</ref><ref>{{cite journal | vauthors = Kumar AS, Kelleher DC, Sigle GW | title = Bowel Preparation before Elective Surgery | journal = Clinics in Colon and Rectal Surgery | volume = 26 | issue = 3 | pages = 146–152 | date = September 2013 | pmid = 24436665 | pmc = 3747288 | doi = 10.1055/s-0033-1351129 }}</ref>

The patient may be asked not to take aspirin or similar products such as [[salicylate]], [[ibuprofen]], etc. for up to ten days before the procedure to avoid the risk of bleeding if a polypectomy is performed during the procedure. A blood test may be performed before the procedure.<ref>{{cite web|url=http://www.pamf.org/gastroenterology/ColyteColon.pdf |title=Colyte/Trilyte Colonoscopy Preparation |access-date=12 June 2007 |date=June 2006 |publisher=Palo Alto Medical Foundation |archive-url=https://web.archive.org/web/20070414032341/http://www.pamf.org/gastroenterology/ColyteColon.pdf |archive-date=14 April 2007 }}</ref>

===Procedure===
[[File:Diagram showing a colonoscopy CRUK 060.svg|thumb|left|Schematic overview of colonoscopy procedure]]

During the procedure, the patient is often given [[sedation]] intravenously, employing agents such as [[fentanyl]] or [[midazolam]]. Although meperidine (Demerol) may be used as an alternative to fentanyl, the concern of seizures has relegated this agent to second choice for sedation behind the combination of fentanyl and midazolam. The average person will receive a combination of these two drugs, usually between 25 and 100{{nbsp}}μg IV fentanyl and 1–4{{nbsp}}mg IV midazolam. Sedation practices vary between practitioners and nations; in some clinics in Norway, sedation is rarely administered.<ref>{{cite journal | vauthors = Bretthauer M, Hoff G, Severinsen H, Erga J, Sauar J, Huppertz-Hauss G | title = [Systematic quality control programme for colonoscopy in an endoscopy centre in Norway] | language = no | journal = Tidsskrift for den Norske Laegeforening | volume = 124 | issue = 10 | pages = 1402–1405 | date = May 2004 | pmid = 15195182 }}</ref><ref>{{cite journal | vauthors = Dossa F, Dubé C, Tinmouth J, Sorvari A, Rabeneck L, McCurdy BR, Dominitz JA, Baxter NN | title = Practice recommendations for the use of sedation in routine hospital-based colonoscopy | journal = BMJ Open Gastroenterology | volume = 7 | issue = 1 | article-number = e000348 | date = 16 February 2020 | pmid = 32128226 | pmc = 7039579 | doi = 10.1136/bmjgast-2019-000348 }}</ref>

The first step is usually a [[digital rectal examination]] (DRE), to examine the tone of the anal [[sphincter]] and to determine if preparation has been adequate. A DRE is also useful in detecting anal [[neoplasm]]s and the clinician may note issues with the prostate gland in men undergoing this procedure.<ref>{{cite journal | vauthors = Farooq O, Farooq A, Ghosh S, Qadri R, Steed T, Quinton M, Usmani N | title = The Digital Divide: A Retrospective Survey of Digital Rectal Examinations during the Workup of Rectal Cancers | journal = Healthcare | volume = 9 | issue = 7 | page = 855 | date = July 2021 | pmid = 34356233 | pmc = 8306048 | doi = 10.3390/healthcare9070855 | doi-access = free }}</ref> The [[endoscopy|endoscope]] is then passed through the [[Human anus|anus]] up the [[rectum]], the [[Colon (anatomy)|colon]] (sigmoid, descending, transverse and ascending colon, the cecum), and ultimately the [[ileum|terminal ileum]]. The endoscope has a movable tip and multiple channels for instrumentation, air, suction and light. The bowel is occasionally insufflated with air to maximize visibility (a procedure that gives the patient the false sensation of needing to take a [[bowel movement]]). Biopsies are frequently taken for [[histology]]. Additionally in a procedure known as [[chromoendoscopy]], a contrast-dye (such as [[indigo carmine]]) may be sprayed through the endoscope onto the bowel wall to help visualize any abnormalities in the mucosal morphology. A [[Cochrane review]] updated in 2016 found strong evidence that chromoscopy enhances the detection of cancerous tumors in the colon and rectum.<ref>{{cite journal | vauthors = Brown SR, Baraza W, Din S, Riley S | title = Chromoscopy versus conventional endoscopy for the detection of polyps in the colon and rectum | journal = The Cochrane Database of Systematic Reviews | volume = 2016 | issue = 4 | article-number = CD006439 | date = April 2016 | pmid = 27056645 | pmc = 8749964 | doi = 10.1002/14651858.CD006439.pub4 }}</ref>

In most experienced hands, the endoscope is advanced to the junction of where the colon and small bowel join up ([[cecum]]) in under 10 minutes in 95% of cases. Due to tight turns and redundancy in areas of the colon that are not "fixed", loops may form in which advancement of the endoscope creates a "bowing" effect that causes the tip to actually retract. These loops often result in discomfort due to stretching of the colon and its associated [[mesentery]]. Manoeuvres to "reduce" or remove the loop include pulling the endoscope backwards while twisting it. Alternatively, body position changes and abdominal support from external hand pressure can often "straighten" the endoscope to allow the scope to move forward. In a minority of patients, looping is often cited as a cause for an incomplete examination. Usage of alternative instruments leading to completion of the examination has been investigated, including use of pediatric colonoscope, push enteroscope and upper GI endoscope variants.<ref>{{cite journal | vauthors = Lichtenstein GR, Park PD, Long WB, Ginsberg GG, Kochman ML | title = Use of a push enteroscope improves ability to perform total colonoscopy in previously unsuccessful attempts at colonoscopy in adult patients | journal = The American Journal of Gastroenterology | volume = 94 | issue = 1 | pages = 187–190 | date = January 1999 | pmid = 9934753 | doi = 10.1111/j.1572-0241.1999.00794.x | s2cid = 24536782 }} ''Note:Single use PDF copy provided free by [[Blackwell Publishing]] for purposes of Wikipedia content enrichment.''</ref>

<gallery>
Image:Endomucosal resection 1.jpg|Polyp is identified.
Image:Endomucosal resection 2.jpg|A sterile solution is injected under the polyp to lift it away from deeper tissues.
Image:Endomucosal resection 3.jpg|A portion of the polyp is now removed.
Image:Endomucosal resection 4.jpg|The polyp is fully removed.
</gallery>

===Patient comfort and pain management===
The pain associated with the procedure is not caused by the insertion of the scope but rather by the inflation of the colon in order to do the inspection. The scope itself is essentially a long, flexible tube about a centimeter in diameter — that is, as big around as the little finger, which is less than the diameter of an average stool.<ref>{{cite journal | vauthors = Ekkelenkamp VE, Dowler K, Valori RM, Dunckley P | title = Patient comfort and quality in colonoscopy | journal = World Journal of Gastroenterology | volume = 19 | issue = 15 | pages = 2355–2361 | date = April 2013 | pmid = 23613629 | pmc = 3631987 | doi = 10.3748/wjg.v19.i15.2355 | doi-access = free }}</ref>

The colon has sensors that can tell when there is unexpected gas pushing the colon walls out—which may cause mild discomfort. Usually, total anesthesia or a partial [[twilight anesthesia|twilight sedative]] are used to reduce the patient's awareness of pain or discomfort, or just the unusual sensations of the procedure. Once the colon has been inflated, the doctor inspects it with the scope as it is slowly pulled backward. If any polyps are found they are then cut out for later biopsy.<ref>{{cite journal |last1=Brown |first1=Shaun |last2=Whitlow |first2=Charles B. |date=1 March 2017 |title=Patient comfort during colonoscopy |url=https://www.sciencedirect.com/science/article/pii/S1043148916300549 |journal=Seminars in Colon and Rectal Surgery |series=SI: Advanced Endoscopy Outline |volume=28 |issue=1 |pages=1–3 |doi=10.1053/j.scrs.2016.11.004 |issn=1043-1489 |url-access=subscription |access-date=10 November 2023 |archive-date=27 February 2024 |archive-url=https://web.archive.org/web/20240227031615/https://www.sciencedirect.com/science/article/abs/pii/S1043148916300549 |url-status=live }}</ref>

Colonoscopy can be carried out without any sedation and a number of studies have been performed evaluating colonoscopy outcomes without sedation.<ref>{{cite journal | vauthors = Zhang K, Yuan Q, Zhu S, Xu D, An Z | title = Is Unsedated Colonoscopy Gaining Ground Over Sedated Colonoscopy? | journal = Journal of the National Medical Association | volume = 110 | issue = 2 | pages = 143–148 | date = April 2018 | pmid = 29580447 | doi = 10.1016/j.jnma.2016.12.003 }}</ref> Though in the US and EU the procedure is usually carried out with some form of sedation.<ref>{{cite journal | url=https://www.giejournal.org/article/S0016-5107(99)70381-0/fulltext | doi=10.1016/S0016-5107(99)70381-0 | title=Patients willing to try colonoscopy without sedation: Associated clinical factors and results of a randomized controlled trial | date=1999 | journal=Gastrointestinal Endoscopy | volume=49 | issue=5 | pages=554–559 | pmid=10228251 | vauthors = Rex DK, Imperiale TF, Portish V }}</ref>

==Economics==
Researchers have found that older patients with three or more significant health problems (i.e., dementia or heart failure) had higher rates of repeat colonoscopies without medical indications. These patients are less likely to live long enough to develop colon cancer.<ref>{{cite web |date=16 March 2023 |title=Health and Economic Benefits of Colorectal Cancer Interventions |url=https://www.cdc.gov/chronicdisease/programs-impact/pop/colorectal-cancer.htm |access-date=7 November 2023 |website=U.S. [[Centers for Disease Control and Prevention]] (CDC) |archive-date=7 November 2023 |archive-url=https://web.archive.org/web/20231107215244/https://www.cdc.gov/chronicdisease/programs-impact/pop/colorectal-cancer.htm |url-status=live }}</ref>

==History==
After Curtiss<ref>{{cite journal | last1=Curtiss |first1=L. E. |last2=Hirschowitz |first2=B. I. |last3=Peters |first3=C. W. | title = A long fiberscope for internal medical examinations | journal = J. Am. Opt. Soc. | volume = 46 | pages = 1030 | date = 1956 }}</ref> succeeded in 1956 in coating long, fine glass fibers – in order to reduce information and light losses during image transmission – and bundling them in parallel, the basis for flexible fiber endoscopy was laid. From Von Hirschowiz's report on the first functioning fiber gastroscope<ref>{{cite journal | last1= Hirschowitz |first1=B. I. |last2=Curtiss |first2=L. E. |last3=Peters |first3=C. W. |last4=Polland |first4=H. M. | title = Demonstration of a new gastroscope, the "fiberscope" | journal = Ann. Meeting Am. Gastroscop. Soc. | location = Colorado Springs, USA | date = May 16, 1957 }}</ref> in 1957, however, it took another 10 years until the limits of rigid rectoscopy could be regularly overcome with a practical fiberscope. The technical requirements for building a fiber endoscope for colon examinations were extensive. A fiber optic bundle for image transmission, a second bundle for illumination, a control system including wires for bending the instrument tip, tubing for air insufflation and a biopsy channel had to be accommodated in a long, flexible, and thin shaft. The technical pioneering work was carried out by the companies ACMI, Eder Instrument Co., Machida, Olympus, and Sass Wolf. They were supported in this effort by – to name just a few – Overholt (USA), Deyhle, Ottenjann (Germany), and Matsunaga, Niwa, Watanabe, and Yamagata (Japan). 

In the 1960s, numerous prototypes were built, which were continually improved (materials, fiber optics, control technology, elasticity, etc.). The first practical fiber sigmoidoscope with a tip that could be bent in two directions and a shaft length of 50 cm was presented by Overholt,<ref>{{cite journal | last1= Overholt |first1=B. F. |last2=Pollard |first2=H. M. | title = Cancer of the colon and rectum, current procedures for the detection and diagnosis | journal = Cancer | volume = 20 | pages = 445–450 | date = 1967 | issue = 3 | doi = 10.1002/1097-0142(1967)20:3<445::AID-CNCR2820200312>3.0.CO;2-9 | pmid = 6021499 }}</ref> in 1967. Niwa<ref>{{cite journal |last1=Niwa |first1=H. |last2=Utsumi |first2=Y. |last3=Kaneko |first3=E. |display-authors=et al | title = Clinical application of colonofiberscope (Japanese) | journal = Gastroenterol. Endosc. | volume = 11 | pages = 163–173| date = 1969 }}</ref> Matsunaga<ref>{{cite journal | last1= Matsunage |first1=F. |last2=Mashima |first2=A. |last3=Uchino |first3=C. |display-authors=et al | title = New large fiberscope (second report) (Japanese)| journal = Gastroenterol. Endosc. | volume = 11 | pages = 219 | date = 1969 }}</ref> and Yamagata<ref>{{cite journal | last1 = Yamagata |first1=K. |last2=Miyura |first2=K. |last3=Watanabe |first3=A. | title = Clinical applications of the large fiberscope Type VII (Japanese) | journal = Gastroenterol. Endosc. | volume = 11 | pages = 219 | date = 1969 }}</ref> reported in 1969 on instruments up to 120 cm long, and Deyhle<ref>{{cite journal | last1=Deyhle |first1=P. |last2=Ottenjann |first2=R. |last3=Paul |first3=F. | title = Die proximale peranale coloskopie | journal = 73. Tagung der Nordwestdeutschen Gesellschaft für Innere Medizin | location = Bremen | pages = 32 | date = 1969 }}</ref> on an instrument with a tip that could be bent in all directions. 

In 1970, Deyhle,<ref>{{cite journal | last= Deyhle |first=P. | title = Fibercolonoscopy | journal = EEOC Congress | location = Munich | pages = cited in Classen, M.: Progress Report. Fiberendoscopy of the Intestines. Gut 12, 330-338, April 1971| date = 1970 }}</ref> Nagasako<ref>{{cite journal | last1=Nagasako |first1=K. |last2=Takemoto |first2=T. |last3=Kondo |first3=T. | title = The insertion of fibercolonoscop into the caecum and direct observation of the ileocaecal valve | journal = Endoscopy | volume = 2 | pages = 121–126 | date = 1970 | doi = 10.1055/s-0028-1098446 }}</ref> and Watanabe<ref>{{cite journal | last1= Watanabe |first1=H. |last2=Narasaka |first2=T. |last3=Uezu |first3=J. |display-authors=et al. | title = An improved fibercolonoscope and its application to colonic diseases | journal = 2nd World Congress of Ganstroint. Endoscopy, Cited in Classen, M.: Progress Report. Fiberendoscopy of the Intestines. Gut 12, 330-338, April 1971 | location = Rome and Kopenhangen | date = 1970 }}</ref> reported successful examinations extending into the cecum using instruments from Machida and Olympus. Watanabe reached the cecum in 8 of 25 cases, and Deyhle in 22 of 28. He described the insertion technique and documented it on film. The world's first paper on a series of colonoscopies describing the preparation for the examination and the colonoscope insertion technique up to the cecum was published by Deyhle in 1971.<ref>{{cite journal | last1= Deyhle |first1=P. |last2=Demling |first2=L. | title = Coloscopy – Technique, results, indication | journal = Endoscopy | volume = 3 | pages = 142–151 | date = 1971 | issue = 3 | doi = 10.1055/s-0028-1098133 }}</ref> Later that same year, the first paper by Wolff and Shinya appeared.<ref>{{cite journal | last1= Wolff |first1=W. |last2=Shinya |first2=H. | title = Colonofiberoscopy | journal = JAMA | volume = 217 | pages = 1509–1512 | date = 1971 | issue = 11 | doi = 10.1001/jama.1971.03190110029007 |pmid=5109748 }}</ref> During the early 1970s, colonoscopy was introduced in numerous endoscopy centers and specialty practices. 

The invention and market for CCD colonoscopy was led by Fujifilm, Olympus, and Hoya in Japan. In 1982, Lawrence Kaplan of the Aspen Medical Group in St. Paul, MN, USA, reported on a series of 100 consecutive colonoscopies and upper endoscopies performed in a freestanding clinic located miles from the nearest hospital to demonstrate the safety and cost-effectiveness of these outpatient procedures. (Personal communication to the Joint Commission on Outpatient Care, May 1983){{fcn|date=October 2025}}

Some of the leading medical device companies in the colonoscopy market as of 2023 include: [[Fujifilm]], [[Karl Storz SE]], Pro Scope Systems, [[Olympus Corporation]], [[Medtronic Plc]], [[Steris]] and [[Pentax]] Medical.<ref>{{cite web |last=Lowden |first=Olivia |title=Top companies and takeaways of the endoscopy devices industry |url=https://blog.bccresearch.com/top-companies-and-market-takeaways-of-the-endoscopy-devices-industry |access-date=17 November 2023 |website=blog.bccresearch.com |archive-date=17 November 2023 |archive-url=https://web.archive.org/web/20231117010321/https://blog.bccresearch.com/top-companies-and-market-takeaways-of-the-endoscopy-devices-industry |url-status=live }}</ref>{{better source needed|date=March 2024}}

===Etymology===
The terms ''colonoscopy''<ref name="Dorland1948">{{cite book | vauthors = Dorland WA, Miller EC | date = 1948 | title = The American illustrated medical dictionary. | edition = 21st | location = Philadelphia/London | publisher = W.B. Saunders Company }}</ref><ref name="Dirckx1997">{{cite book | veditors = Dirckx JH | date = 1997 | title = Stedman's concise medical dictionary for the health professions. | edition = 3rd | location = Baltimore | publisher = Williams & Wilkins }}</ref><ref name="Dorland2000">{{cite book | vauthors = Anderson DM | date = 2000 | title = Dorland's illustrated medical dictionary | edition = 29th | location = Philadelphia/London/Toronto/Montreal/Sydney/Tokyo| publisher = W.B. Saunders Company }}</ref> or ''coloscopy''<ref name="Dirckx1997"/> are derived from<ref name="Dirckx1997"/> the ancient Greek noun κόλον, same as English ''colon'',<ref name="Liddell & Scott">{{cite book | vauthors = Liddell HG, Scott R | date = 1940 | title = A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie. | location = Oxford | publisher = Clarendon Press }}</ref> and the verb σκοπεῖν, ''look (in)to'', ''examine''.<ref name="Liddell & Scott"/> The term ''colonoscopy'' is however ill-constructed,<ref name="Anastassiades2008">{{cite journal | vauthors = Anastassiades CP, Cremonini F, Hadjinicolaou D | title = Colonoscopy and colonography: back to the roots | journal = European Review for Medical and Pharmacological Sciences | volume = 12 | issue = 6 | pages = 345–347 | date = 2008 | pmid = 19146195 }}</ref> as this form supposes that the first part of the compound consists of a possible root {{lang|grc|κολων}}- or {{lang|grc|κολον}}-, with the connecting vowel -{{lang|grc|o}}, instead of the root {{lang|grc|κόλ}}- of {{lang|grc|κόλον}}.<ref name="Anastassiades2008"/> A compound such as {{lang|grc|κολωνοειδής}}, {{gloss|like a hill}},<ref name="Liddell & Scott"/> (with the additional -on-) is derived from the ancient Greek word κολώνη or {{lang|grc|κολωνός}} {{gloss|hill}}.<ref name="Liddell & Scott"/> Similarly, colonoscopy (with the additional -on-) can literally be translated as "examination of the hill",<ref name="Anastassiades2008"/> instead of the "examination of the colon".

In English, multiple words exist that are derived from κόλον, such as ''colectomy'',<ref name="Dirckx1997"/><ref name="Foster1891">{{cite book |last=Foster |first=F. D. |date=1891–1893 |title=An illustrated medical dictionary. Being a dictionary of the technical terms used by writers on medicine and the collateral sciences, in the Latin, English, French, and German languages |location=New York |publisher=D. Appleton and Company}}</ref>{{page needed|date=October 2025}} ''colocentesis'',<ref name="Dirckx1997"/> ''colopathy'',<ref name="Dirckx1997"/> and ''colostomy''<ref name="Dirckx1997"/> among many others, that actually lack the incorrect additional -on-. A few compound words such as ''colonopathy'' have doublets with -on- inserted.<ref name="Dirckx1997"/><ref name="Dorland2000"/>

==Society and culture==
The procedure of colonoscopy gained national attention in the [[United States]] in 1985 when [[President of the United States|President]] [[Ronald Reagan]] underwent a life-saving colonoscopy.<ref name="pmid19476902">{{cite journal |vauthors=Wiedeman JE |title=Presidential operations: medical fact or urban legend? |journal=J Am Coll Surg |volume=208 |issue=6 |pages=1132–7 |date=June 2009 |pmid=19476902 |doi=10.1016/j.jamcollsurg.2009.01.024 |url=}}</ref><ref name="pmid10996587">{{cite journal |vauthors=Selby JV |title=Explaining recent declines in colorectal cancer incidence: was it the sigmoidoscope? |journal=Am J Med |volume=109 |issue=4 |pages=332–4 |date=September 2000 |pmid=10996587 |doi=10.1016/s0002-9343(00)00540-4 |url=}}</ref><ref name="pmid25901884">{{cite journal |vauthors=Gilbert RE |title=The politics of presidential illness. Ronald Reagan and the Iran-Contra Scandal |journal=Politics Life Sci |volume=33 |issue=2 |pages=58–76 |date=2014 |pmid=25901884 |doi=10.2990/33_2_58 |s2cid=41674696 |url=}}</ref>

A survey on colonoscopy shows a poor understanding of its protective value and widespread misconceptions. The public has perceptual gaps around the purpose of colonoscopies, the subjective experience of the colonoscopy procedure, and the quantity of bowel preparation needed.<ref name="pmid32437402">{{cite journal |vauthors=Amlani B, Radaelli F, Bhandari P |title=A survey on colonoscopy shows poor understanding of its protective value and widespread misconceptions across Europe |journal=PLOS ONE |volume=15 |issue=5 |article-number=e0233490 |date=2020 |pmid=32437402 |pmc=7241766 |doi=10.1371/journal.pone.0233490 |bibcode=2020PLoSO..1533490A |url= |doi-access=free }}</ref>

Actors [[Ryan Reynolds]] and [[Rob McElhenney]] have used their social media platform to raise awareness about the importance of colonoscopy as a procedure for [[colon cancer screening]]. They filmed their own colonoscopies as part of a campaign called "Lead From Behind",<ref>{{cite web |title=Ryan Reynolds and Rob McElhenney Share Their Colonoscopy Videos To Encourage People to 'Lead From Behind' |url=https://www.ccalliance.org/blog/press-releases/ryan-reynolds-rob-mcelhenney-share-colonoscopy-videos-encourage-people-lead-from-behind |access-date=14 November 2023 |website=Colorectal Cancer Alliance |archive-date=14 November 2023 |archive-url=https://web.archive.org/web/20231114195836/https://www.ccalliance.org/blog/press-releases/ryan-reynolds-rob-mcelhenney-share-colonoscopy-videos-encourage-people-lead-from-behind |url-status=live }}</ref><ref>{{cite web |date=13 September 2022 |title=Ryan Reynolds And Rob McElhenney Film Each Other Getting Colonoscopies |url=https://uproxx.com/tv/ryan-reynolds-rob-mcelhenney-colonoscopy-video-lead-from-behind/ |access-date=14 November 2023 |website=UPROXX |archive-date=14 November 2023 |archive-url=https://web.archive.org/web/20231114195834/https://uproxx.com/tv/ryan-reynolds-rob-mcelhenney-colonoscopy-video-lead-from-behind/ |url-status=live }}</ref> demonstrating that the procedure can be both easy and lifesaving.<ref>{{cite news |url=https://edition.cnn.com/2022/09/14/entertainment/ryan-reynolds-rob-mcelhenney-colonoscopy-video-wellness/index.html |title=Ryan Reynolds and Rob McElhenney get a colonoscopy on camera to raise awareness |date=14 September 2022 |access-date=13 November 2023 |archive-date=13 November 2023 |archive-url=https://web.archive.org/web/20231113232106/https://edition.cnn.com/2022/09/14/entertainment/ryan-reynolds-rob-mcelhenney-colonoscopy-video-wellness/index.html |url-status=live }}</ref><ref>{{cite news |url=https://www.webmd.com/colorectal-cancer/news/20220914/actors-bring-awareness-to-colonoscopies |title=Celebrity Actors Film Their Colonoscopies to Bring Awareness |access-date=13 November 2023 |archive-date=13 November 2023 |archive-url=https://web.archive.org/web/20231113232107/https://www.webmd.com/colorectal-cancer/news/20220914/actors-bring-awareness-to-colonoscopies |url-status=live }}</ref>

== References ==
{{Reflist}}

== Further reading ==
{{refbegin}}
* {{cite journal | vauthors = Gupta S, Lieberman D, Anderson JC, Burke CA, Dominitz JA, Kaltenbach T, Robertson DJ, Shaukat A, Syngal S, Rex DK | title = Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer | journal = Gastroenterology | volume = 158 | issue = 4 | pages = 1131–1153.e5 | date = March 2020 | pmid = 32044092 | pmc = 7672705 | doi = 10.1053/j.gastro.2019.10.026 }}
* {{cite journal | vauthors = Gupta S, Lieberman D, Anderson JC, Burke CA, Dominitz JA, Kaltenbach T, Robertson DJ, Shaukat A, Syngal S, Rex DK | title = Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer | journal = The American Journal of Gastroenterology | volume = 115 | issue = 3 | pages = 415–434 | date = March 2020 | pmid = 32039982 | pmc = 7393611 | doi = 10.14309/ajg.0000000000000544 }}
* {{cite journal | vauthors = Joseph DA, King JB, Dowling NF, Thomas CC, Richardson LC | title = Vital Signs: Colorectal Cancer Screening Test Use - United States, 2018 | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 69 | issue = 10 | pages = 253–259 | date = March 2020 | pmid = 32163384 | pmc = 7075255 | doi = 10.15585/mmwr.mm6910a1 }}
{{refend}}

== External links ==
* {{Commons category inline|Colonoscopy}}

{{Digestive system surgical procedures}}
{{Endoscopy}}
{{Portal bar | Medicine}}
{{Authority control}}

[[Category:Cancer screening]]
[[Category:Diagnostic gastroenterology]]
[[Category:Endoscopy]]
[[Category:Large intestine]]