Introduction Chronic diarrhoea is a common reason for referral to gastroenterology departments and often multiple investigations are undertaken. Bile acid malabsorption is an under recognised cause of chronic diarrhoea and currently occupies a lower tier in the investigatory pathway. SeHCaT scanning has been available in our region for the last 2 years and therefore the aim of this study was to investigate the role that this test has in such patients.

Methods All patients referred for a SeHCaT scan were identified by searching by procedure in the Nuclear Medicine department. Patient demographics, indication, number of previous tests, surgical history and SeHCaT result were noted. The cut off for an abnormal test was < 15% retention at 7 days. Notes were reviewed to determine which patients had treatment and the response rate. In those with a negative result, the final diagnosis (if known) was recorded.

Results 122 patients (95 female, median age 50 years) had undergone a SeHCaT scan for investigation of chronic diarrhoea during the period January 2011 to July 2012. 61/122 (50%) patients had a SeHCaT retention < 15% with 30 having retention values < 5%, 19 between 5.1 – 10% and 12 between 10.1 – 15%. An abnormal SeHCaT scan was associated with previous bowel surgery (Odds ratio 14.2, 95% CI 1.8–113.1, p = 0.002) but not gender (odds ratio 2.0 95% CI 0.8–4.7, p = ns) or previous cholecystectomy (odds ratio 1.2 95% CI 0.5–2.7, p = ns). 45/53 (84.9%) patients were commenced on bile acid sequestrants (mainly cholestyramine) with a good response to treatment. 13 patients were intolerant of cholestyramine and switched to colesevalam of which 10 have so far had clinical improvement. Prior to SeHCat scanning patients had undergone a median of 2.5 other investigations (range 0 – 9). Final diagnosis was bile acid diarrhoea (n = 61), irritable bowel syndrome (n = 34), malabsorption (n = 3), Crohns disease (n = 2), coeliac disease (n = 1), diverticular disease (n = 1), small bowel bacterial overgrowth (n = 1) and still being investigated (n = 19).

Conclusion In patients with chronic diarrhoea, SeHCaT scanning has a high yield and is associated with good clinical response to treatment with cholestyramine. We did not find that previous cholecystectomy was a risk factor but confirm that bowel resection appears to be. Switching to colesevalam is effective when cholestyramine is not tolerated.

Disclosure of Interest None Declared.