Long-term course in collagenous colitis and the impact of bile acid malabsorption and bile acid sequestrants on histopathology and clinical features

Background: Bile acid malabsorption is common in collagenous colitis, altho ugh long-term follow-up data on the impact of bile acids are limited. The a im was to study whether bile acid malabsorption is a permanent finding, wit h an impact on histopathology and clinical features in collagenous colitis. Methods: The objective was to reinvestigate 27 patients with collagenous c olitis greater than or equal to3 years after index investigation. The clini cal course was evaluated by means of an interview. a review of the hospital records and registration of symptoms over a period of 7 days. The patients were invited to undergo a repeat colonoscopy and (75)SeHCAT measurement. I nitial and follow-up data and 75SeHCAT values from 29 controls were compare d. Results: The median follow-up time was 4.2 (range 3-5.3) years. Twenty-t wo patients underwent a repeat (75)SeHCAT test, 23 patients a colonoscopy a nd in 15 patients the clinical course could be evaluated. The (75)SeHCAT va lues were abnormal in 32% at follow-up versus 44% at index, and the median retention value was 19% (range 2-69) versus 12% (range 0.51-41) (P=0.024) a lthough lower than in the control groups figure of 38% (range 8-91) (P < 0. 005). Histopathology had improved independently of bile acid malabsorption, gender, smoking and autoimmune disease at followup. Four were normalized. Patients on bile acid binders had no significant change of histopathology. Four patients had recovered. seven displayed an intermittent course and 14 had continuous diarrhoea. Conclusions: Collagenous colitis and bile acid ma labsorption seem to be associated yet independent disorders. The histopatho logy improves during the long-term course although only a few patients reso lve.