ERCP (Endoscopic Retrograde Cholangiopancreatography) is a diagnostic and therapeutic procedure that uses an endoscope to examine the bile ducts, pancreatic ducts, and the gallbladder. During an ERCP procedure, a flexible tube called an endoscope is passed through the mouth, esophagus, stomach, and duodenum (the first part of the small intestine) to reach the bile and pancreatic ducts.

Once the endoscope is in place, a small catheter is passed through it and contrast dye is injected into the ducts. X-ray images are then taken to evaluate the ducts for any abnormalities, such as gallstones, tumors, or strictures (narrowing of the ducts).

If any abnormalities are found, the ERCP procedure can also be used to perform therapeutic interventions. For example, a small instrument can be passed through the endoscope to remove gallstones or place stents in the ducts to relieve obstructions.

ERCP is a complex procedure that requires specialized training and expertise. It is typically performed by a gastroenterologist who has received additional training in ERCP. It is usually done under sedation or general anesthesia and can take anywhere from 30 minutes to 2 hours, depending on the complexity of the case.