Attention is drawn to the results of a study of 45 patients with bile duct calculosis designed to assess the soundness and the limits of two diagnostic examinations (HIDA and PTC) in determining the morphological and functional characteristics of the hepatoenteric tract. The results indicated that HIDA is a useful first step in average to serious cases of icterus as a means of evaluating the functional state of liver cells and the bile ducts by determination of activity-time curves for preselected areas, whereas PTC is more important in cases of serious icterus, since it also enables the patient to be suitably prepared for surgery.