Mo1972 Role of SeHCAT Scanning in Diagnosis of Bile Salt Malabsorption: a University Hospital Experience

Abstract

Introduction: Chronic diarrhoea is a very common presentation in the gastroenterology clinics. Majority of patients with negative investigations for organic disease are often labelled with a diagnosis of irritable bowel syndrome with diarrhoea (IBS-D). Bile salt malabsorption (BMA) is not an uncommon cause of chronic diarrhoea. In clinical practice mostly an empirical trail of bile acid sequestrants is used to diagnose this condition which lacks diagnostic accuracy. 23-seleno-25-homo-tauro-cholic acid (SeHCAT) scan is a reliable, simple and non invasive investigation to detect and treat this condition but has been underutilized in most centres in the United Kingdom (UK). Aims & Methods: We aimed to evaluate the usefulness of SeHCAT scan in evaluating patients with chronic diarrhoea. We retrospectively reviewed all patients who had SeHCAT scan over a two year period in a University Hospital. The integrated hospital electronic database system was reviewed and analysed for the following: clinical details, radiology, biochemistry, endoscopy and histology. BMA was defines as SeHCAT retention of less than 15% (mild 10-15%; moderate 5-10% and severe <5%). Results: 118 patients referred to gastroenterology clinic for chronic diarrhoea underwent SeHCAT testing over the review period. 42 M; 76 F, mean age 51 y (range 16-89). SeHCAT test was positive for BMA in 51/118(43%) of patients. Among positive SeHCAT tests, 27 (53%) had severe, 15 (29%) had moderate and, 9 (17%) had mild BAM. 12 (23%) had type 1 (6 terminal ileal resection and 6 Crohn's Disease), 28 (55%) had type 2 (Idiopathic) and 11 (21.5%) had type 3 (7 cholecystectomy, 2 diabetes, 2 coeliac) BAM. Out of 51 with confirmed BMA on SeHCAT testing, treatment information in the notes was available for 35(68%) of the patients. These patients were treated with bile acid sequestrants, either with colesevalam (n=7) or with cholestyramine (n=28). Colesevalam was well tolerated with 100% good response. In cholestyramine group 12(43%) had good response, 4(7%) partial and 7(25%) showed poor response. All patients with poor response discontinued treatment and 4 (57%) of this group stopped cholestyramine early due to unpleasant side effects. No treatment response was documented in the notes for 5 patients. Overall, colesevalam had excellent response rates with no reported side effects. Conclusion: SeHCAT scan is probably an underutilized test for diagnosing bile salt malabsorption. In patients presenting with chronic diarrhoea SeHCAT scanning must be considered to diagnose this probably under recognised cause of chronic diarrhoea. Colesevalam has better tolerability and response rates and must be considered in group of patients intolerant to cholestyramine.