(CIT): ERCP is a procedure used by physicians to diagnose and treat problems in the liver, gallbladder, bile ducts, and pancreas. It combines the use of x-rays and an endoscope--a long, flexible, lighted tube. The physician inserts the endoscope in a patient's mouth and guides it down through the esophagus and into the stomach and small intestine. ERCP allows the physician to look inside these organs and also to send dye to the bile and pancreatic ducts, thereby making them visible on an x-ray.