Gallstones can be reliably induced in rabbits by the addition of 3-beta-cholestanol to an otherwise normal diet. This initial observation of Bevans and Mosbach (2) has been confirmed by others (3, 6, 8) and has been found to be a useful experimental model. In the rabbit, cholestanol is metabolized and excreted in the bile as a glycine-conjugated salt of allodeoxycholic acid (4). While deoxycholic acid is a normal component of bile in both man and rabbit, its stereoisomer allodeoxycholic acid is not. This abnormal component of bile is not as soluble in bile as its stereoisomer, and this is thought to be the factor responsible for its precipitation in the gallbladder. This precipitation of abnormal bile acid cannot be compared with cholelithogenesis in man. Gallstones in man consist of precipitated components of the normal constituents of bile. Despite this shortcoming, the suitability of the rabbit gallbladder to study by intravenous cholecystography provides an excellent opportunity to examine the roentge...