Endoscopic retrograde cholangiopancreatography, or ERCP, is a specialized technique used to study the bile ducts, pancreatic duct and gallbladder. Ducts are drainage routes; the drainage channels from the liver are called bile or biliary ducts. The pancreatic duct is the drainage channel from the pancreas.
During ERCP, your doctor will pass an endoscope through your mouth, esophagus and stomach into the duodenum (first part of the small intestine). An endoscope is a thin, flexible tube that lets your doctor see inside your bowels. After your doctor sees the common opening to the ducts from the liver and pancreas, called the major duodenal papilla, your doctor will pass a narrow plastic tube called a catheter through the endoscope and into the ducts. Your doctor will inject a contrast material (dye) into the pancreatic or biliary ducts and will take X-rays.