Objective: Collagenous colitis is a chronic watery diarrhea disorder characterized by a subepithelial collagen layer and a lymphoplasmacytic infiltration within the lamina propria. However, no standard treatment has been introduced by controlled clinical trials. Aim of the present pilot trial was to investigate the clinical effects of orally administered budesonide (3 mg t.i.d.) in 7 patients with collagenous colitis. In addition, the histomorphological changes after budesonide treatment were described in a group of 3 patients.
Methods: The study was performed as an open label pilot trial. Study end point was the clinical remission of collagenous colitis defined by stool frequency and stool consistency.
Results: The results indicate a rapid and sustained clinical response in all patients. Stool frequency significantly decreased (p < 0.001) from 10.43 +/- 5.56 per day (4-20 per day) to 3.3 +/- 1.2 (1-5 per day) after 10 days and to 1.86 +/- 0.69 per day (1-3 per day) after 10 wk. Moreover stool consistency changed from watery (6 patients) or soft (1 patient) to soft (1 patient) or solid (6 patients). Clinical improvement was achieved within the first 10 days in all patients and maintained after dose reduction. In 3 patients no diarrhea recurred within 7, 12, or 15 months after treatment with budesonide was terminated. In these patients control biopsies were taken and showed a marked regression of both characteristics, the collagen band and the lymphoplasmacytic infiltration.
Conclusions: With respect to the preliminary data from this pilot trial, budesonide with its high topical and low systemic effects seems to be of therapeutic clinical benefit in collagenous colitis. A therapeutic effect could be demonstrated for both therapeutic goals, the clinical response and morphological changes. Further studies on the effects of budesonide on mucosal collagen metabolism and long-term follow-up are warranted.