Endoscopic retrograde cholangiopancreatography, or ERCP, is an endoscopic technique that is used to examine and treat problems in the bile and pancreatic ducts, and the gallbladder. The bile ducts are channels, analogous to plumbing, that drain bile from the liver and gallbladder; the pancreatic ducts drain the pancreas. Both types of ducts empty into the duodenum, which is the first part of the small intestine.

ERCP may be performed for a variety of reasons. The most common reason is to find and remove gallstones lodged within the bile duct. However, other reasons can include finding causes of persistent pain in the upper abdomen on the right side, looking for causes of acute pancreatitis (acute inflammation of the pancreas) and to relieve obstruction of the bile duct caused by tumors such as pancreas cancer. Often, in many of these situations, an ultrasound of the abdomen or a special kind of MRI study called MRCP may be performed to obtain preliminary information that can guide the need for ERCP.

ERCP is performed by gastroenterologists who are specially trained in this technique. An endoscope is a long, flexible tube with a camera and a light at the tip. First, you will be adequately sedated with general anesthesia. The endoscope or tube is placed into the mouth and advanced into the esophagus, stomach, and to the point in the duodenum where the bile duct enters; this is known as the papilla. A plastic catheter (thin tube) is threaded through the scope to come out its tip and then is maneuvered to enter the papilla and the ducts. Contrast dye (radio-opaque material) is then injected into the ducts and x-rays are taken. By examining the ducts in this way, information about blockages, stones, tumors, or irregularities of the ducts can be gathered. If abnormalities are found, the doctor can perform techniques to repair or improve the condition. For example, if stones are seen, the papilla can be widened or cut open and stones may be removed from the duct. The papilla contains a sphincter muscle that is often cut using cautery (the passage of electric current) during the procedure (sphincterotomy), which allows for better duct drainage.