Interventions for treating lymphocytic colitis.

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. To determine effective treatments for patients with clinically active lymphocytic colitis. 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 December 2007. 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. The trial registry website www.ClinicalTrials.gov was searched to identify registered but unpublished trials. Finally, the Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies. Five randomized controlled trials were identified. Three of these studies, which assessed bismuth subsalicylate vs. placebo, budesonide vs. placebo, and mesalazine vs. mesalazine vs. cholestyramine in treating active disease, are included in this review. Data were extracted independently by each author onto 2x2 tables (treatment versus placebo or active comparator and response versus no response). For therapies assessed in one trial only, P values were derived using the chi-square test. Forty-one patients were enrolled in the trial studying budesonide (9 mg/day for 6 weeks versus placebo). Budesonide was more effective than placebo at inducing both clinical (P = 0.004; NNT = 3) and histological responses (P = 0.04; NNT = 3). Forty-one patients were enrolled in the study assessing mesalazine versus mesalazine plus cholestyramine. A high proportion of patients in each group responded to treatment. However, no statistically significant difference in clinical response was found between the two treatment groups (P = 0.95). Five patients were enrolled in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks vs. placebo). There were no differences in clinical (P=0.10) or histological responses (P=0.71) in patients treated with bismuth subsalicylate compared with placebo. A single trial studying budesonide suggests that it may be effective for the treatment of active lymphocytic colitis. An ongoing placebo-controlled trial may confirm the benefit of budesonide. There is weaker evidence that mesalazine with or without cholestyramine may be effective for the treatment of lymphocytic colitis, but this benefit needs to be confirmed in a placebo-controlled study. No conclusions can be made regarding bismuth subsalicylate. These agents require further study before they can be recommended as treatment options for lymphocytic colitis. Further trials studying interventions for lymphocytic colitis are warranted.