Colonic perforation as a complication of collagenous colitis in a series of 12 patients.

Objectives: The rare complication of colonic perforation in collagenous colitis following colonoscopy or barium enema is reported in this series of 12 patients.

Methods: Patients with collagenous colitis complicated by perforation were collected from the authors' consultation files between 1992 and 2007. Colectomy and biopsy specimens were reviewed and the corresponding clinical data were analyzed.

Results: The patients ranged in age from 44 to 80 yr, with a female-to-male ratio of 11:1. Perforation occurred during colonoscopy in 2 patients, within 0-5 days following colonoscopy in 8 patients, and during barium enema in 2 patients. The most notable colonoscopic findings were bleeding linear ulcers of the right colon in 9 patients, several of which developed under direct visualization during endoscopy. The perforation culminated in right hemicolectomy in 11 patients. Linear fissuring ulcers were identified in the resections of 8 patients along with features of perforation, including pneumatosis in 4 patients and barium extravasation within the muscularis propria in 2 patients.

Conclusions: This is the largest published series to date, and the first to uncover several novel clinicopathologic features of perforation in collagenous colitis, including the right colonic predilection (corresponding to disease severity), the association with not only colonoscopy, but also barium enema, the occurrence of recognizable perforation actually developing during the procedure, and a more detailed information on the marked histologic severity of these patients' collagenous colitis. An awareness of this rare but potentially fatal complication of collagenous colitis may facilitate its diagnosis and management.