Prospective Evaluation of Terminal Ileitis in a Surveillance Population of Patients with Ulcerative Colitis.

Background: Ulcerative colitis (UC) is a disease that is normally limited to involvement of the colon. Terminal ileitis in patients with UC with only inactive or mildly active disease has never been investigated. The aim of this prospective study was to determine the prevalence and significance of ileitis among patients with UC enrolled in an endoscopic surveillance program.

Methods: The study consisted of 72 patients with UC and 90 healthy controls who underwent surveillance and screening colonoscopy, respectively. The endoscopic and histologic features of the terminal ileum (both groups) and colon (UC group only) were evaluated in a standardized fashion. Extensive clinical and endoscopic information was obtained from the subjects, and these data were compared between patients with UC either with or without ileitis.

Results: Sixteen of 72 patients with UC (22%) had ileitis compared to only 4 of 90 (4%) of the non-UC controls (P < 0.001). None of the patients had features of backwash. Among patients with UC, the presence of ileitis showed a trend towards correlation with extent of disease, but a significant association with involvement of the colonic side of the ileocecal valve (P = 0.02) was noted. Alcohol use in the week before the colonoscopy was also significant (P = 0.02). There were no other features that were significantly related to ileitis in the patients with UC. Only one UC case with ileitis developed Crohn's disease on follow-up.

Conclusions: Ileitis in patients with UC may represent a primary extracolonic manifestation of UC in patients with inactive or mild disease and is not due to backwash.