Bile acid malabsorption investigated by selenium-75-homocholic acid taurine (75SeHCAT) scans, a retrospective single-centre experience.

BACKGROUND

Bile acid malabsorption (BAM) is a common entity in patients experiencing chronic watery diarrhea. However, literature suggests that BAM is underdiagnosed and undertreated. In many countries 75SeHCAT is the gold standard for diagnosing BAM (1-5). The aim of this retrospective study was to investigate the frequency of BAM using 75SeHCAT scintigraphy and the response to treatment with bile acid sequestrants.

METHODS

We retrospectively evaluated the clinical data of 420 patients who had a 75SeHCAT scan from January 2016 to January 2023. Electronic medical records were investigated for risk factors of BAM. BAM was defined as a 75SeHCAT retention of less than 15%. Response to bile acid sequestrants was evaluated based on outpatient clinical reports.

RESULTS

Median age at the time of 75SeHCAT test was 47 years (range 14-87). Out of 420 patients, 192 (46%) had a positive result for BAM. Cholecystectomy and ileal resection were significant predictors for BAM (p<0.001). BAM type 1 is statistically more likely to be more severe compared to type 2 (p<0.0001) and compared to type 3 (p=0.0021). In patients who fulfilled Rome IV criteria for IBS-D or functional diarrhea, 75 out of 121 (38%) tested positive for BAM. Overall, treatment with bile acid binders was effective in 76%.

CONCLUSIONS

This retrospective study of patients who underwent SeHCAT scanning confirms that about 1/3 patients presenting with therapy-resistant chronic diarrhea in secondary care suffer from BAM. Including the test in clinical management protocols of chronic diarrhea allows early and quantitative diagnosis and treatment of BAM.