1.What is ERCP? ERCP is to insert the duodenoscope into the descending duodenum, find the duodenal papilla, insert a contrast catheter through the endoscopic orifice, and enter the duodenal papilla, inject contrast agent, if the pancreatic duct and bile duct are visualized at the same time or successively, it is called ERCP. With the development of medical technology, ERCP has gradually evolved from a simple diagnostic imaging to a modern diagnostic technique combining cytology, histology, pancreatic fluid and bile biochemistry, tumor marker detection and genetic diagnosis; there is also rapid development in therapeutic ERCP, including endoscopic papillary sphincterotomy, lithotomy, bile duct stent drainage, nasobiliary duct drainage, bile duct multi-stent duct drainage, biliopancreatic duct double-stent drainage, pancreatic duct sphincterotomy, pancreatic duct lithotomy, nasopancreatic duct drainage At present, the Department of Gastroenterology of Shanghai Tenth People’s Hospital can perform the above operations. 2.What diseases are suitable for ERCP? It is generally considered that all suspected pancreaticobiliary diseases are indications, mainly including: (1) suspected bile duct stones, tumors, inflammation, parasites or obstructive jaundice with unknown causes. (2) Recurrence of symptoms after cholecystectomy or bile duct surgery. (3) Clinical suspicion of pancreatic tumor, chronic pancreatitis or recurrent pancreatitis in remission. (4) Suspected of inflammation or tumor of the duodenal papilla or jugular abdomen, and biliary pancreatitis to remove the cause. (5) Those suspected of having congenital malformations such as common bile duct cysts and pancreaticobiliary duct confluence abnormalities. (6) Unexplained epigastric pain with suspected pancreaticobiliary tract disease. (7) Those who need to collect bile or pancreatic fluid or perform Oddi sphincter manometry due to biliopancreatic disorders. (8) Those who need endoscopic treatment due to pancreaticobiliary disorders. (9) Suspected pancreatic duct rupture after pancreatic trauma. (10) Bile leakage after bile duct surgery and suspected misinjury. (11) Suspected congenital lesions of the pancreas. (12) Certain liver disorders, such as hepatocellular carcinoma with obstructive jaundice, intra- and extra-hepatic bile duct stones with intrahepatic cholangitis. It is worth noting that acute cholangitis (even a part of acute purulent obstructive cholangitis), biliary acute pancreatitis and pancreatic cysts, which used to be considered as contraindications to ERCP, are now considered not contraindicated due to the development of duodenoscopic drainage technology in recent years, but have become the preferred treatment method, and endoscopic diagnostic treatment should be performed as soon as possible when conditions are available.