Present features of gallstones in Japan. A collective review of 2,144 cases.

A collective review of 2,144 patients operated on for cholelithiasis during the last twenty-two months has shown that younger Japanese adults have predominantly cholesterol stones in their gallbladders and that elderly persons still frequently have bilirubin stones not only in their gallbladders but also in their common bile ducts. Recent westernization of dietary habits in Japan is considered to be the most probable factor causing the increased incidence of cholesterol stones. The decreased incidence of bilirubin stones is considered to be caused by the decreased incidence of biliary infection and increased intake of proteins in food.