Introduction Bile acid malabsorbtion (BAM) is a known cause of chronic diarrhoea. The condition is easily diagnosed by performing a selenium homocholic acid taurine (SeHCAT) test, with 7-day retention of <10% indicating BAM. BAM negatively impacts on quality of life but responds well to bile acid sequestrants. Patients with undiagnosed BAM are often labelled as diarrhoea-predominant IBS (IBS-D), especially those with idiopathic or type 2 BAM. We aimed to investigate the clinical characteristics of patients diagnosed with type 2 BAM.

Method We performed a retrospective study of patients who underwent a SeHCAT scan for investigation of diarrhoea at the Royal Liverpool Hospital between 18/03/2009 and 03/01/2012. Clinical details including demographics and response to treatment were abstracted from electronic case notes.

Results 161 patients who attended for SeHCAT scan for investigation for diarrhoea were reviewed. 60 patients had BAM with a 7 day Selenium retention of <10%.

22 of these patients had primary (type 2) BAM, of which 12 were female and 10 were male, median age 48.5 (range 23–68). 12 of these patients were labelled as IBS-D by their clinicians prior to the SeHCAT test. 19 received treatment with bile acid sequestrants. 13 had follow up data, 6 are awaiting clinic review and 3 patients were lost to follow up. 12 (92%) of the 13 patients reviewed in clinic responded well to treatment, taken as significant reduction in bowel frequency or dramatic improvement suggested by the patient. 1 (8%) patient did not respond despite 2 different bile acid sequestrants.

35 of the remaining 38 patients had secondary BAM due to ileal Crohn's (57%), cholecystectomy (20%), intestinal resection (8.5%), both cholecystectomy and ileal Crohn's (5.7%), coeliac disease (5.7%), and chronic pancreatitis (2.9%). Of these patients 23 were female and 12 were male, median age 45 (range 16–80). 30 patients received treatment with bile acid sequestrants. 23 had follow up data, and 7 are awaiting clinic review. 20 (87%) of the 23 patients reviewed in clinic responded well to treatment and 3 (13%) did not respond despite 2 different bile acid sequestrants.

Conclusion BAM is a cause of chronic diarrhoea that can be easily managed with bile acid sequestrants. Patients with chronic diarrhoea and in particular those who have been labelled as IBS-D should be referred for a SeHCAT scan to rule out BAM. If the test is not available locally then referral to another centre should be considered.