Types of Gallstones

Cholesterol stones are usually white or yellow and account for about 80% of gallstones. Cholesterol stones develop when bile contains too much cholesterol and not enough bile salts. In these situations, the gallbladder is often slow in emptying. This causes a build up of bile, and it becomes very concentrated. Crystallization of the cholesterol in the bile causes stone formation.

The other 20% of gallstones are small dark pigment stones made of bilirubin and calcium salts. Risk factors for pigment stones include cirrhosis, biliary tract infections, and hereditary blood cell disorders like sickle cell anemia.