Gallstones

In medicine, gallstones (choleliths) are crystalline bodies formed within the body by accretion or concretion of normal or abnormal bile components. Cholesterol stones are usually green, but are sometimes white or yellow in color and account for about 80 percent of gallstones. They are made primarily of cholesterol. Pigment stones are small, dark stones made of bilirubin and calcium salts that are found in bile. They account for the other 20 percent of gallstones. Risk factors for pigment s ...