Budesonide treatment of collagenous colitis: a randomised, double blind, placebo controlled trial with morphometric analysis.

BACKGROUND Collagenous colitis is characterised by diarrhoea, lymphocytic inflammation, and a thickened subepithelial collagen layer in the colorectal mucosa. No standard treatment of the disease is established. AIMS To investigate the clinical and histological effect of oral budesonide (Entocort, AstraZeneca) in the treatment of collagenous colitis. PATIENTS Twenty patients with collagenous colitis (collagen layer >10 micro m) and diarrhoea (>4 stools/day and/or stool weight >200 g/day). METHODS A randomised, double blind, placebo controlled trial of budesonide treatment. Patients were randomised to placebo or budesonide for eight weeks. Stool frequency and stool weight were registered before and after treatment. Sigmoidoscopy was performed before and after treatment, and biopsies at fixed locations were obtained for morphometric analysis. RESULTS Ten patients were randomised to budesonide and 10 to placebo. All 10 patients receiving budesonide had a clinical response compared with two in the placebo group (p<0.001). In the budesonide group, stool weight was reduced from 574 g/day to 200 g/day and stool frequency was reduced from 6.2/day to 1.9/day (p<0.01). The histological inflammation grade in the sigmoid mucosa and the thickness of the collagen layer were significantly reduced. A correlation between the grade of inflammation as well as collagen layer thickness and stool weight was found. No side effects were reported. Eight of 10 patients had relapse of symptoms within eight weeks after stopping treatment. CONCLUSIONS Budesonide is a highly effective and well tolerated treatment of collagenous colitis. There is a high risk of relapse after stopping eight weeks of treatment.