Intra- and extrahepatic impairment of biliary drainage is important in the pathogenesis of liver disease in cystic fibrosis. Distal common bile duct obstruction is reported to occur in 13% to 96% of these patients. Between 1975 and 1993, 17 of 372 children (4.5%) with cystic fibrosis attending The Children's Memorial Medical Center in Chicago had liver disease based on clinical and laboratory findings.