Introduction Bile acid malabsorption (BAM) is a common cause of chronic diarrhoea that can be diagnosed by the SeHCAT test and treated with bile acid sequestrants (BAS). The purpose of this study was to clarify the use and efficacy of BAS in the treatment of patients with diarrhoea and equivocal SeHCAT results.

Methods Case records were reviewed over a 6-year period for patients investigated by SeHCAT with a positive (≤8%), equivocal (>8% and <16%) or negative (>16%) retention result. Patients were sub-characterised into the following groups. Group 1: terminal ileum Crohn's disease, (pre or post resection) n=51. Group 2: diarrhoea predominant irritable bowel syndrome (D-IBS) n=159. Group 3: BAM associated with other gastrointestinal disease n=51; of which cholecystectomy (n=37), coeliac disease (n=1), chronic pancreatitis (n=1), bacterial overgrowth (n=2), diabetes (n=4) and other gastrointestinal surgeries (n=6). Group 4: terminal ileum disease plus cholecystectomy n=3. Patients' sex and age were recorded. Use of BAS (colestyramine or colesevelam) and response were noted.

Results SeHCAT tests were performed in 264 patients and 39 (15%) patients were found to have equivocal results while 104 (39%) had positive results. Although 28/39 (72%) patients with equivocal results were offered treatment with BAS, information on response to treatment was only available in half of these patients (n=14). In comparison, there was a higher rate (75%) of follow-up in the patients with positive SeHCAT results with information on response to treatment being available in 73 of the 97 patients offered BAS treatment. There was a marked difference in response to BAS therapy between the two groups. A successful response was noted in only 36% (n=5) of patients with equivocal SeHCAT results while 66% (n=48) of patients with positive SeHCAT results had a successful response. The difference in treatment response was also most significant among the patients in group 2 with D-IBS. 73% (n=24/33) of the patients with positive SeHCAT results in group 2 responded to BAS therapy while only 33% (n=3/9) of those with equivocal SeHCAT results in this same group had a successful response.

Conclusion This retrospective study indicates that there is a poorer response to bile acid sequestrants among patients with equivocal SeHCAT results, however it is possible there was a disproportionate number of non-responders attending for follow-up in this group. More comprehensive follow-up is needed in patients with equivocal SeHCAT results in the future to help determine whether BAS treatment in this lower response group is cost-effective.

Competing interests None declared.