Abstract
A gallstone is defined as a concrement present in the biliary tract consisting of the gallbladder and bile duct. The etiological process of gallstones is different in terms of the location and composition. Gallstones are classified as cholesterol, pigment, and rare gallstones according to the main component (Japanese Gastroenterological Society, Committee for the Study of Cholelithiasis, 1986). The prevalence and category of gallstones in Japan are approaching those of the West; the proportion of cholesterol stones increased up to 70% of the gallbladder stones, and that of black pigment stones in the gallbladder also increased. While gallstone pathogenesis differs with respect to stone category, the process of stone formation consists of hypersecretion of main components in gallstones into bile, the crystallization and precipitation of the components in the bile, and then the rapid growth of the precipitated crystals. The knowledge of biliary physiology, e.g., formation, secretion and concentration of bile, is necessary for a better understanding of gallstone pathogenesis. This paper reviews the issue of classification and pathogenesis of gallstones in reference to the clinical practice guidelines for gallstone diseases published in 2009 (Japanese Gastroenterological Society).
