Background: Microscopic colitis is a disease of unknown aetiology characterized by chronic watery diarrhoea and diarrhoea can be eliminated by budesonide but frequently recurs when budesonide is stopped. We studied whether prednisolone could induce remission in patients with disabling, chronic diarrhoea due to microscopic colitis.
Methods: A double-blind, randomized (3:1) trial of oral prednisolone 50 mg daily or placebo for 2 weeks. Remission was defined as stool weight < or = 200 g/day or frequency < or = 2/day; effect was defined as > 50% reduction of either stool frequency or weight. Six centres screened 31 consecutive patients and included 11 with collagenous colitis and 1 with lymphocytic colitis. Median duration of diarrhoea was 9 months. Patients had a normal colonoscopy, and no evidence of coeliac disease, bile acid or lactose malabsorption. Patients with gastrointestinal infection, previous gastrointestinal surgery, abnormal biochemical screening or recent treatment with immunosuppressive agents were excluded.
Results: Stool weight (grams) declined in 7 of 9 patients given prednisolone and in 1 of 3 receiving placebo; changes in median weight were from 430 to 278 and from 825 to 489, respectively. Stool frequency (per day) declined from 6 to 3 and from 8 to 5. Remission was obtained in 2 and 0, and effect in 5 and 0, respectively (NS; Fisher exact test).
Conclusions: Prednisolone 50 mg daily for 2 weeks induces incomplete remission in patients with chronic diarrhoea due to collagenous colitis.