Does colonoscopy cause increased ulcerative colitis symptoms?

BACKGROUND Ulcerative colitis (UC) patients often report symptom flares after colonoscopy. However, this has not been documented in the literature. OBJECTIVES 1. Determine whether colonoscopy is associated with increased UC symptoms. 2. Determine whether there is a need for escalation of UC medications after colonoscopy. 3. Identify baseline variables associated with increased symptoms after colonoscopy. METHODS Fifty-five outpatients with a history of UC, intact colon, and quiescent disease were enrolled in a prospective case-crossover study. Subjects were evaluated with the Simple Clinical Colitis Activity Index (SCCAI) before colonoscopy, 1 week and 4 weeks after colonoscopy. A mixed model analysis was used to accommodate nonindependence of repeated measurements on the same patients. RESULTS Fifty-one (91%) subjects completed the study. Six subjects had clinical relapse defined by a score of 5 or greater on the SCCAI during the week after colonoscopy. Five subjects increased their 5-aminosalicylic acid (5-ASA) medications immediately postcolonoscopy, two of whom had a SCCAI 5 or greater. Multivariate modeling demonstrated a clear association between the week immediately after colonoscopy preparation and increased disease activity, with the time period being predictive of increased SCCAI (week 1 vs. week 4, P = 0.0127). The baseline SCCAI (P value < 0.0001) and prednisone use (P = 0.0120) were predictive of increased SCCAI postcolonoscopy. Thiopurines (P < 0.001) were protective against increased symptoms. CONCLUSIONS In our study, 1 in 8 subjects had UC relapse by SCCAI immediately postcolonoscopy, and 1 in 10 subjects required an increase in their 5-ASA medications. Clinicians should be cognizant of this effect of colonoscopy in patients with UC.