Do you know ghouls from goblins and ghosts?
gallstone gall·stone (gôl'stōn')
A concretion in the gallbladder or in a bile duct, composed chiefly of cholesterol, calcium salts, and bile pigments. Also called biliary calculus, cholelith.
A hard, pebblelike material deposited in the gallbladder or bile ducts by the process of chemical precipitation. Gallstones can cause considerable pain and can even obstruct the flow of bile from the gallbladder. On some occasions, the entire gallbladder must be removed by surgery.