diversion colitis
{{Infobox medical condition (new)
| name = Diversion colitis
| synonyms =
| image = Diversion proctitis - intermed mag.jpg
| width =
| caption = Micrograph showing colonic-type mucosa with follicular lymphoid hyperplasia, as is seen in diversion colitis. H&E stain.
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| field = Gastroenterology
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| complications =
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| types =
| causes = Surgery with diversion of colon (ileostomy or colostomy)
| risks =
| diagnosis =
| differential =
| prevention =
| treatment = Short-chain fatty acid enemas
| medication = Mesalazine
| prognosis =
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Diversion colitis is an inflammation of the colon which can occur as a complication of ileostomy or colostomy, where symptoms may occur between one month and three years following surgery.{{cite journal | vauthors = Tominaga K, Kamimura K, Takahashi K, Yokoyama J, Yamagiwa S, Terai S | title = Diversion colitis and pouchitis: A mini-review | journal = World Journal of Gastroenterology | volume = 24 | issue = 16 | pages = 1734–1747 | date = April 2018 | pmid = 29713128 | pmc = 5922993 | doi = 10.3748/wjg.v24.i16.1734 | doi-access = free }} It also occurs frequently in a neovagina created by colovaginoplasty, with varying delay after the original procedure.{{cite journal | vauthors = van der Sluis WB, Bouman MB, Meijerink WJ, Elfering L, Mullender MG, de Boer NH, van Bodegraven AA | title = Diversion neovaginitis after sigmoid vaginoplasty: endoscopic and clinical characteristics | journal = Fertility and Sterility | volume = 105 | issue = 3 | pages = 834–839.e1 | date = March 2016 | pmid = 26632208 | doi = 10.1016/j.fertnstert.2015.11.013 | doi-access=free }} Despite the presence of a variable degree of inflammation the most suggestive histological feature remains the prominent lymphoid aggregates.
Symptoms and signs
People may be asymptomatic but common symptoms are abdominal discomfort, anorectal pain, mucous discharge and rectal bleeding that develops from the inflamed mucosa of the distal, unused colon.
Diagnosis
Diagnosis is aided by knowing the full clinical history.{{cite journal | vauthors = Haboubi, Haboubi | title = Reporting colonic mucosal biopsies in inflammatory conditions: a new approach | journal = Colorectal Disease | volume = 2 | issue = 2 | pages = 66–72 | date = April 2000 | pmid = 23577987 | doi = 10.1046/j.1463-1318.2000.00104.x| s2cid = 40271111 }}
Treatment
In many milder cases after ileostomy or colostomy, diversion colitis is left untreated and disappears naturally. Possible pharmacologic treatments include short-chain fatty acid irrigation, steroid enemas and mesalazine.{{cite journal |doi=10.1136/gut.32.9.1020|vauthors=Geraghty JM, Talbot IC |title=Diversion colitis: histological features in the colon and rectum after defunctioning colostomy |journal=Gut |volume=32 |issue=9 |pages=1020–3 |date=September 1991 |pmid=1916483 |pmc=1379042 |url=}} For surgical candidates, reanastomosis is a reversal procedure carried out to restore bowel continuity that effectively halts the symptoms of diversion colitis.