Objectives: To conduct a systematic review to determine effective treatments for patients with clinically active collagenous colitis.
Methods: Relevant articles were identified via the MEDLINE, PUBMED, and Cochrane Collaboration databases, manual searches of the references of identified articles, and review articles on collagenous or microscopic colitis, as well as searches of abstracts from major gastroenterological meetings.
Results: Five randomized trials assessing treatments for collagenous colitis were identified. One trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 wk) included 9 patients. Patients who received the bismuth preparation were more likely to have clinical (p= 0.003) and histological (p= 0.003) improvement than those who received placebo. In a trial comparing prednisolone (50 mg daily for 2 wk) to a placebo in 11 patients, a trend toward clinical response in patients on prednisone was reported (p= 0.064). The effect of prednisolone on histological improvement was not studied. A total of 94 patients were enrolled in three trials studying budesonide (9 mg daily or in a tapering schedule for 6-8 wk). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI: 5.53-27.46). The NNT (number of patients needed to treat with budesonide to achieve 1 improved patient) was 2 patients. This therapy was well tolerated. There was significant histological improvement with treatment in all three trials studying budesonide therapy.
Conclusions: There is strong evidence that budesonide is effective and well tolerated for the treatment of collagenous colitis. The evidence for benefit with bismuth subsalicylate or prednisolone is weaker. It is not clear that any of these agents produce actual remission, as opposed to clinical and histological improvement of the disease.