Bile acid malabsorption: an under-investigated differential diagnosis in patients presenting with diarrhea predominant irritable bowel syndrome type symptoms.

OBJECTIVE: Bile acid malabsorption (BAM) has been reported as a possible cause of diarrhea predominant irritable bowel syndrome (D-IBS) type symptoms. We aimed to determine how commonly patients with D-IBS type symptoms had a diagnosis of BAM as demonstrated by a positive SeHCAT (75 Selenium-homocholic acid taurine) test (retention <10% at seven days).

MATERIALS AND METHODS: A retrospective analysis was undertaken of patient's records for all patients who underwent a SeHCAT test between 2001 and 2009 in a tertiary hospital (Group A). Concurrently, a cohort of patients with Rome II D-IBS type symptoms was examined to determine the potential utility of SeHCAT test (Group B).

RESULTS: In Group A 39.2% (n = 107/273) of patients had a positive SeHCAT result. The median time from first hospital visit to SeHCAT result was 30 weeks. Predictive factors for BAM: terminal ileal Crohn's disease (p < 0.01), terminal ileal resection (p < 0.01), and previous cholecystectomy (p < 0.01). 33.6% of patients who had a positive SeHCAT also had Rome II D-IBS. In Group B the D-IBS control cohort only 1.9% of patients had undergone a SeHCAT scan (p < 0.001 compared to Group A).

CONCLUSION: BAM is common and should be considered earlier when investigating unselected patients with D-IBS type symptoms.