Bile salts are formed from cholesterol and conjugated in the liver, excreted via the biliary system into the duodenum, reabsorbed in the ileum, stored temporarily in the hepatic bile salt pool, and reexcreted into the biliary system. This normal enterohepatic circulation of bile salts is both efficient and rapid. Interruption of the enterohepatic circulation of bile salts may cause cholesterol cholelithiasis or oxalate urolithiasis. Clinical and radiologic features of pediatric patients with gallstones and urolithiasis secondary to abnormalities of the ileum are reported. The pathophysiology of lithiasis due to interruption of the enterohepatic circulation of bile salts is discussed. This enteric cause is included in the differential diagnosis of cholelithiasis and urolithiasis in infants and children.