Some observations on gallstones and bile composition.

A series of 31 consecutive patients undergoing surgery for gallstone disease has been studied and the composition of the gallstones and bile from the gallbladder and common duct determined. As a result of the stone analysis by the X-ray powder diffraction method, the patients were classified according to whether their stones consisted of cholesterol, calcium salts or a mixture of the two. The mean composition of the common duct bile for the groups with cholesterol and mixed stones was just outside the micellar region of cholesterol solubility. The gallbladder bile from the cholesterol group of stone-formers was also supersaturated, but the gallblader bile from the group of mixed stone-formers was undersaturated with respect to cholesterol. None of the patients forming gallstones of calcium salts showed any abnormality in the cholesterol content of their bile.