Comparison of three bile acid provocation tests. Intravenous cholecystokinin, a standard test meal, and an oral bile acid load in healthy subjects.

Three different bile acid provocation tests--an intravenous stimulation with cholecystokinin (CCK), a test meal, and an oral bile acid load of 500 mg chenodeoxycholic acid (CDA)--were compared in 12 healthy subjects. Blood samples were drawn every 30 min for 3 h, and serum bile acids (SBA) were measured by an enzymatic method (Enzabile). The CCK stimulation gave significant SBA elevations only at 30 min. After the test meal and the CDA loading tests SBA elevations were observed from 30 min and throughout the observation period. Maximal increases were obtained at 120 min after the test meal but already at 30 min after the CDA loading test. We conclude that among these three bile acid provocation tests the oral CDA loading test is to be preferred because it gives marked and rapid elevation of SBA in all subjects and is independent of bile acid pool size and normal function of the gallbladder.