In simplest terms, cholestasis is defined as a decrease in bile flow. The clinical manifestations of cholestasis occur because of accumulation of substances normally excreted in the bile; namely bilirubin, bile acids, and cholesterol. Accumulation of bilirubin leads to jaundice and dark urine. Accumulation of bile acids is associated with pruritus, and accumulation of cholesterol causes hypercholesterolemia and xanthomas. There are many causes of cholestasis in early infancy ranging from normal physiologic jaundice to complete biliary obstruction associated with biliary atresia.