IDIOPATHIC BILE-ACID MALABSORPTION - QUALITATIVE AND QUANTITATIVE CLINICAL-FEATURES AND RESPONSE TO CHOLESTYRAMINE

Background: Idiopathic bile acid malabsorption is a poorly recognized cause of chronic diarrhoea. The SeHCAT ((75)Selenium HomotauroCholic A cid Test) can accurately diagnose this condition. Aim: To identify pat ients with idiopathic bile acid malabsorption, to describe their clini cal features, both qualitatively and quantitatively, and to assess the response to cholestyramine, Method: Idiopathic bile acid malabsorptio n was considered in all patients complaining of chronic diarrhoea. The y were included in the study if their SeHCATs were positive (< 15% ret ention) and secondary causes of bile acid malabsorption were excluded. The response to therapy with cholestyramine was assessed. Results: Ni ne patients were diagnosed with idiopathic bile acid malabsorption (me dian SeHCAT retention 8%, range 3-12.6), Their median daily faecal wei ght was 285 g (range 85-676) and median faecal fat output was 17 mmol/ 24 h (range 8.3-38.8), Six patients had an immediate response to chole styramine. There was a marked reduction in stool frequency (median sto ol frequency pre-treatment 5/day vs, 2/day post-treatment, P = 0.03). Five patients had large volume diarrhoea (faecal weight > 200 g/day) a nd three had steatorrhoea, Conclusions: Idiopathic bile acid malabsorp tion, once suspected, especially by documenting true 'large volume' wa tery diarrhoea pr steatorrhoea, is easily diagnosed and response to th erapy is often very good, There is often a previous history of gastroi ntestinal infection and this condition should be considered in patient s with chronic diarrhoea of undetermined origin, especially before the y are labelled as having irritable bowel syndrome.