683 Audit of Introducing Fecal Bile Acid Diagnostic Test in Evaluation of Diarrhea in Patients With Inflammatory Bowel Disease in a Tertiary Care Center

Abstract

INTRODUCTION: Patients with inflammatory bowel disease (IBD), whether Crohn's disease (CD) or ulcerative colitis (UC), have known alterations in the enterohepatic circulation of bile acids (BA) that may contribute to chronic diarrhea, but the fecal BA patterns are not well defined. We aimed to audit all patients with IBD who had fecal BA measurements as part of evaluation of chronic diarrhea at a tertiary care center. METHODS: Methods: 65 patients with IBD (18 with UC and 47 with CD) were evaluated at a single center and underwent measurements of fecal total and individual BAs based on a 48-hour collection performed at the end of a 4-day, 100-gram fat diet. The electronic medical records were interrogated to obtain type of IBD, disease activity, location of disease, prior surgery, IBD related therapies, presenting symptoms, and response to treatment with BA sequestrants. Bile acid diarrhea (BAD) diagnosis was based on >10% primary BAs, >4% primary BAs + >1,000 µmol/48 h, or total fecal BAs >2,337 µmol/48 h. IBD disease activity was based on radiologic, endoscopic and histologic parameters. Data are reported as mean ± standard error of the mean (SEM). RESULTS: Table 1 summarizes the patterns of BAD in our cohort with IBD. Figure 1 demonstrates the mean ± SEM of total fecal BAs and % primary BAs in each group of IBD patients. Among patients with UC, 10 had poorly controlled disease and 8 had well controlled disease, and both cohorts had elevated primary BAs (mean 28.9% ± 12.5%; 34.6% ± 21%, respectively). All patients with an ileal pouch anal anastomosis (IPAA) had elevated total fecal BAs (BADt) compared to those with an intact colon. In patients with CD, those with ileal resections had elevated BADt and % primary BAs (6263 µmol/48 h ± 1012 µmol/48 h; 79% ± 5.9%, respectively). Patients with an intact ileum, had elevated % primary BAs regardless of disease activity: controlled CD 34.7% ± 9.3%; poorly controlled CD 57.8% ± 9.5%; 15 out of 47 patients with CD were started on BA sequestrants with a positive response in 10/15. CONCLUSION: Discussion: BAs may play a role in the pathophysiology of chronic diarrhea in patients with IBD, regardless of inflammatory disease activity. Future studies are required to assess the impact of fecal bile acid testing and treatment with BA sequestrants on inflammation and chronic diarrhea in patients with IBD.