Pathophysiology of gallstone formation.

Research on gallstone formation has been focused on the role of supersaturated bile in cholesterol gallstone disease. But now investigators have advanced the concept of nucleation, which holds that the interaction of pronucleators and antinucleators is responsible for the formation of cholesterol crystals and the subsequent development of gallstones. Ultrasonography can identify biliary sludge, the chemical composition of which appears to depend on the type of medical disorder present. The chemical composition of sludge will determine the composition of the gallstones--either cholesterol stones or pigment stones--that eventually form. Nonsurgical interventions, such as bile acids, are effective in the treatment of cholesterol gallstones, which account for approximately 80% of cases that develop in Western populations. Bile acids are not effective in treating calcium bilirubinate stones.