Interventions for treating lymphocytic colitis

Background Lymphocytic colitis is a cause of chronic diarrhea. Therapy is based mainly on case series and uncontrolled trials, or by extrapolation of data for treating collagenous colitis, a related disorder. This review was performed to identify therapies for lymphocytic colitis that have been proven in randomized controlled trials. Objectives To determine effective treatments for patients with clinically active lymphocytic colitis. Search strategy The MEDLINE, PUBMED and EMBASE databases were searched using the search criteria "microscopic colitis" or "lymphocytic colitis" and "treatment" or "therapy" or "management" to identify relevant papers published between 1970 and September 2006. Manual searches from the references of identified papers and relevant review papers were performed. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register was searched for other studies. Selection criteria A single randomized trial published in abstract form only which studied bismuth subsalicylate was identified, and included only 5 patients with lymphocytic colitis (and 9 with collagenous colitis). Data collection and analysis Data were extracted independently by each author onto 2x2 tables (treatment versus placebo and response versus no response). For therapies assessed in one trial only, P values were derived using the chi-square test. Main results There were 5 patients with lymphocytic colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks vs. placebo). Although all three patients on active drug experienced clinical improvement compared to none of the placebo group, there were no statistically significant differences in clinical (P = 0.10) or histological (P = 0.71) improvement. Authors' conclusions A single trial studying bismuth subsalicylate as therapy for lymphocytic colitis suggests that it may be beneficial. However, it included only 5 patients and no firm conclusions can be made from such a small trial. Larger trials studying treatments for lymphocytic colitis are warranted.