Cholic acid and chenodeoxycholic acid

Bile acids are water-soluble cholesterol breakdown products which are secreted into the bile

They recirculate in bile, aiding fat absorption in the intestine

Diseases affecting hepatic function and GI absorption affect serum bile acid levels

Since absorption problems can generally be separated from hepatocellular disease on clinical grounds, bile acids are relatively specific for hepatobiliary disease–but are nonspecific within that category

Bile acid levels are considered to be the most sensitive indicator of hepatic or biliary disease: they may be abnormal in inactive cirrhosis and late convalescent hepatitis when other tests are normal

Normal bile acids in a 2-hour postprandial specimen are a strong indication that the liver and biliary tree are normal.