Introduction Bile acid diarrhoea (BAD) is an under-diagnosed cause of diarrhoea and there is a suggestion that up to a third of patients with previously diagnosed diarrhoea-predominant irritable bowel syndrome have BAD diagnosed by a tauroselcholic [⁷⁵selenium] acid (SeHCAT) scan.¹ BAD risk factors include ileal resection (IR), right hemicolectomy (RH), radiotherapy (RT), cholecystectomy and Crohn’s (CD) but it is unclear whether SeHCAT scans add value to these patient groups.¹ This single-centre retrospective study evaluates SeHCAT scans in patients with/without risk factors and their responses to bile acid sequestrants (BAS).

Methods We retrospectively evaluated the clinical data of all 269 patients who had a SeHCAT scan from February 2011 to December 2014. Patients with cholecystectomy, CD, RH/IR or previous pelvic RT were compared to those without BAD risk factors. Clinic correspondences were evaluated for presenting symptoms and BAD risk factors, treatment with BAS and their tolerance/effectiveness. Response was measured as good or absent according to patient report to physician. Seven cases were excluded due to absence of clinical data. Statistical analyses were calculated for each individual case group versus the control group with no risk factors for BAD. P-values were adjusted with Bonferroni correction.

Results Average age at time of scan was 53.8. M:F was 1:2.74. 115/262 had BAD confirmed with a SeHCAT scan of <11%. Table 1 shows the scan results for each case group and analyses comparing each to the control group. Three groups were identified as having increased risk of BAD: cholecystectomy, quiescent CD (ileal and colonic) and RH/IR. Colestyramine was trialled in 100 BAD cases, 84% had a good response but 38% tolerated therapy. Colesevelam was trialled in 64 BAD cases, 84% had a good response and 48% tolerated therapy.

Conclusion We demonstrate that a history of cholecystectomy, CD or RH/IR with chronic diarrhoea is highly suggestive of BAD. Of the six CD patients without BAD, four had isolated colonic disease. Pelvic RT did not increase risk of BAD. A SeHCAT scan can cost £486² whilst a month’s trial of either BAS costs <£40³ and have high response rates in BAD. Given the high probability of a positive scan in cases of RH/IR we suggest trials of empirical BAS could be used instead of SeHCAT for diagnosis in these patients.

References 1 L Wedlake, et al. AP&T 2009;30:707–717.

2 NICE. Diagnostic guidance DG7, 2012.

3 BNF 2012;64.

Disclosure of Interest None Declared