Comparison between SeHCAT test and clinical response to cholestyramine in patients with chronic diarrhea and high suspicion of bile acid malabsorption: A single‐center prospective study

Objectives We aimed to evaluate the clinical response to cholestyramine in patients with functional chronic diarrhea and a high clinical suspicion of bile‐acid diarrhea (BAD) investigated with 75‐selenium homocholic acid taurine (SeHCAT) test. Methods Adult patients attending our outpatient clinic between January and December 2021 for chronic diarrhea with suspicion of BAD were proposed SeHCAT testing and a therapeutic trial of cholestyramine 4–8 g daily. Clinical response to cholestyramine was evaluated at 1, 3, 6, and 12 months. Clinical and demographic data were analyzed according to SeHCAT test results. Results Among the 50 patients with chronic diarrhea and clinical suspicion of BAD, 13 (26.0%) refused either SeHCAT testing or cholestyramine therapy. Finally, 37 patients (31 females, age 44 ± 14 years) agreed to undergo SeHCAT and were started on cholestyramine (median follow‐up 14 months [interquartile range 6–16 months]). Initial response to cholestyramine was similar in patients with positive and negative SeHCAT test results, but improved over time in those with a positive test result. Long‐term response (100% vs 65.2%, P = 0.02) and necessity of maintenance therapy for symptom control were more common in those with positive SeHCAT test result (71.4% vs 26.1%, P = 0.02). However, response to cholestyramine was also frequent in patients with a negative test result. Conclusions The SeHCAT test accurately identifies patients with BAD who benefit from long‐term cholestyramine treatment. Nevertheless, cholestyramine may be also effective in patients with chronic diarrhea but negative SeHCAT test result.