Editing Ulcerative colitis (section)

===Endoscopic===
[[Image:Chronic Ulcerative Colitis 1.jpg|thumb|Colonic [[pseudopolyps]] of a person with intractable UC, [[colectomy]] specimen]]
The best test for diagnosis of ulcerative colitis remains [[endoscopy]], which is examination of the internal surface of the bowel using a flexible camera. Initially, a flexible sigmoidoscopy may be completed to establish the diagnosis.<ref name="Lamb" /> The physician may elect to limit the extent of the initial exam if severe colitis is encountered to minimize the risk of [[Bowel perforation|perforation]] of the colon. However, a complete colonoscopy with entry into the terminal ileum should be performed to rule out Crohn's disease, and assess extent and severity of disease.<ref name="Lamb">{{cite journal | vauthors = Lamb CA, Kennedy NA, Raine T, Hendy PA, Smith PJ, Limdi JK, Hayee B, Lomer MC, Parkes GC, Selinger C, Barrett KJ, Davies RJ, Bennett C, Gittens S, Dunlop MG, Faiz O, Fraser A, Garrick V, Johnston PD, Parkes M, Sanderson J, Terry H, Gaya DR, Iqbal TH, Taylor SA, Smith M, Brookes M, Hansen R, Hawthorne AB | title = British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults | journal = Gut | volume = 68 | issue = Suppl 3 | pages = s1–s106 | date = December 2019 | pmid = 31562236 | pmc = 6872448 | doi = 10.1136/gutjnl-2019-318484 }}</ref> Endoscopic findings in ulcerative colitis include: [[erythema]] (redness of the [[mucosa]]), [[friability]] of the mucosa, superficial ulceration, and loss of the vascular appearance of the colon. When present, ulcerations may be confluent. Pseudopolyps may be observed.<ref>{{cite journal | vauthors = Politis DS, Papamichael K, Katsanos KH, Koulouridis I, Mavromati D, Tsianos EV, Christodoulou DK | title = Presence of pseudopolyps in ulcerative colitis is associated with a higher risk for treatment escalation | journal = Annals of Gastroenterology | volume = 32 | issue = 2 | pages = 168–173 | date = March 2019 | pmid = 30837789 | pmc = 6394261 | doi = 10.20524/aog.2019.0357 }}</ref>

Ulcerative colitis is usually continuous from the rectum, with the rectum almost universally being involved. Perianal disease is rare. The degree of involvement endoscopically ranges from proctitis (rectal inflammation) to left sided colitis (extending to descending colon), to extensive colitis (extending proximal to descending colon).<ref name=":1" />