Systematic review with meta-analysis: the prevalence of bile acid malabsorption in the irritable bowel syndrome with diarrhoea

BackgroundIrritable bowel syndrome is a widespread disorder with a marked socioeconomic burden. Previous studies support the proposal that a subset of patients with features compatible with diarrhoea-predominant IBS (IBS-D) have bile acid malabsorption (BAM). AimTo perform a systematic review and meta-analysis to assess the prevalence of BAM in patients meeting the accepted criteria for IBS-D. MethodsMEDLINE and EMBASE were searched up to March 2015. Studies recruiting adults with IBS-D, defined by the Manning, Kruis, Rome I, II or III criteria and which used 23-seleno-25-homotaurocholic acid (SeHCAT) testing for the assessment of BAM were included. BAM was defined as 7day SeHCAT retention of <10%. We calculated the rate of BAM and 95% confidence intervals (CI) using a random effects model. The methodological quality of included studies was evaluated using the Quality Assessment for Diagnostic Accuracy Studies (QUADAS-2). ResultsThe search strategy identified six relevant studies comprising 908 individuals. The rate of BAM ranged from 16.9% to 35.3%. The pooled rate was 28.1% (95% CI: 22.6-34%). There was significant heterogeneity in effect sizes (Q-test (2)=17.9, P<0.004; I-2=72.1%). The type of diagnostic criteria used or study country did not significantly modify the effect. ConclusionsThese data provide evidence that in excess of one quarter of patients meeting accepted criteria for IBS-D have bile acid malabsorption. This distinction has implications for the interpretation of previous studies, as well as contemporaneous clinical practice and future guideline development.