The Etiology of Pigment Gallstones
J. Donald Ostrow – 1 September 1984 – Pigment gallstones are of two major types, black and earthy brown, each consisting of calcium salts of bilirubin and other anions, along with an unmeasured residue that is largely mucin glycoproteins. Studies in model systems indicate that the small proportion of unconjugated bilirubin in bile is solubilized by bile salts and that the ionized bilirubin is more soluble than the protonated diacid. Solubility is decreased by added lecithin but is unaffected by cholesterol.