Bile acid malabsorption demonstrated by SeHCAT in chronic diarrhoea, with special reference to the impact of cholecystectomy.

SeHCAT is a gamma-labelled synthetic bile acid, suitable for external measurements and detection of bile acid malabsorption. In this study 138 subjects were investigated with 75SeHCAT. The technique was modified by calculating the biologic half-life of the isotope (WBR-50) within 48 h. All patients with ileocaecal resection had reduced WBR-50 values, as did most (8 of 12) with Crohn's disease affecting the small bowel. Among patients with chronic diarrhoea 24 out of 62 patients had reduced WBR-50 values. Four of the patients with low WBR-50 and one in the group with normal WBR-50 had previously been cholecystectomized. In a consecutive study, 15 patients were investigated before and after cholecystectomy. In 12, WBR-50 decreased after the operation (p less than 0.05). The results demonstrate the impact of cholecystectomy on the interpretation of the SeHCAT retention results. The results may also add to the understanding of diarrhoea secondary to cholecystectomy.