During these 12 years, congenital choledochal dilatation has been experienced in 45 children. Clinical analysis was made as related to symptoms such as abdominal pain, palpable mass, jaundice and etc.. In all of the 12 patients examined, an anomalous junction of the pancreaticobiliary ductal system was demonstrated. Results : (1) There were statistical relationships between abdominal pain or vomiting, and elevated serum amylase level. (2) The patients presenting abdominal pain often tended to show high amylase level in bile. These evidences suggest that in these patients, there occurs the reflux of the bile into the pancreatic duct and the pancreatic juice into the bile duct. It is probable that abdominal pain often accompanied with congenital choledochal dilatation is due to pancreatitis.
