gallstone

Definition gallstone

gallstone: gallstone n. a hard mass composed of bile pigments, cholestrol, and calcium sults, in varying proportions, that can form in the gall bladder. The formation of gallstones (cholelithiasis) occurs when the physical characteristics of bile alter so that cholestrol is less soluble, though chronic inflammation of the gall bladder (see cholecystitis) may also be a contributory factor. Gallstones may exist for many years without causing symptoms. However, they may cause severe pain (see biliary colic) or they may pass into the common bile duct and cause obstructive *jaundice or *cholangitis. Gallstones containing calcium may be seen as a plain X-ray (opaque stones), but if their calcium content is low they can be seen only by *cholecystography. Cholelithiasais is treated by surgical removal of the gall bladder or the stones themselves.