30th July 2023

Biliary causes

The biliary tree is a vital part of the body’s absorption system, through the production and reabsorption of bile acids, which are essential for fat absorption. Bile acids are produced in the liver and then stored and released by the gallbladder. Reabsorption occurs in the terminal ileum.

Any disease affecting the biliary tract can lead to bile acid malabsorption (BAM), as well as those affecting the ileum. This includes primary biliary cholangitis, primary sclerosing cholangitis, gallbladder stones, Crohn’s disease, coeliac disease, pancreatic insufficiency, bacterial overgrowth, or following cholecystectomy or bowel resection.

BAM causes a distinct non-bloody pungent diarrhoea (steatorrhoea), which is generally chronic. The diagnostic test used to be the selenium homocholic acid taurine (SeHCAT) test, but NICE recommendations now advise treatment trials, 48-hour total stool bile acid levels, and fasting C4 levels instead.

Treatment involves a low fat diet and bile acid binders, such as cholestyramine.