Bile acids are part of the thick liquid called bile that helps the body to digest fats. Bile is produced by the liver, stored in the gallbladder, and released into the small intestine where food is digested.

Normally, most of the bile acids used in digestion collect in the last part of the small intestine (ileum) and are returned to the gallbladder and used again. A small amount is lost in the stool and must be replaced by the liver.