Linear mucosal defect may be characteristic of lansoprazole-associated collagenous colitis

Background: Although some cases of collagenous colitis have been induced by lansoprazole (LPZ), the clinicopathologic features of LPZ-associated collagenous colitis have not been elucidated. Objective: To elucidate the clinical, endoscopic, and histopathologic features of LPZ-associated collagenous colitis. Design: Retrospective case study. Patients: The subjects were 13 patients with collagenous colitis diagnosed during a period from 2002 to 2007. Main Outcome Measurements: The colonoscopic and histopathologic findings were compared retrospectively between 9 cases of LPZ use (LPZ group) and 4 cases without the use of LPZ (non-LPZ group). Results: A colonoscopy revealed a linear mucosal defect more frequently in the LPZ group (7 of 9 cases [78%]) than in the non-LPZ group (0 of 4 cases [0%], P =.02). Friable mucosa was also noted in 4 patients (44%) in the LPZ group but none in the non-LPZ group. The colonoscopic finding in the non-LPZ group was either normal mucosa or nonspecific minimal abnormalities, whereas patients in the LPZ group had either a linear mucosal defect, mucosal bleeding, or both (P =.001). On histologic examination, the subepithelial collagen band was thicker in patients in the LPZ group than in those in the non-LPZ group (median 45 vs 26.3 mu m). All patients in the LPZ group recovered from diarrhea after discontinuance of LPZ. Limitation: A small number of patients. Conclusions: Linear mucosal defects and friable mucosa may be characteristic colonoscopic findings in cases of LPZ-associated collagenous colitis.