Pigment gallstones are particularly prevalent in the Far East, especially in association with malaria and parasitic diseases. They are composed of a mixture of calcium bicarbonate, complex bilirubin polymers, bile acids and other unidentified substances. The incidence is similar in men and women, and in blacks and whites. They tend to affect an older age group than the cholesterol and mixed stones. They are rare in American Indians.
Last reviewed 01/2018