Editing Colonoscopy (section)

==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 | pages = 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 [[anaesthesia]], 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=http://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 | pages = 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 |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 |pages=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 |url-status=dead }}</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>