Endoscopic Retrograde Cholangiopancreatography (ERCP) is an endoscopic procedure used to identify the presence of stones, tumors, or narrowing in the biliary and pancreatic ducts. After the endoscope is properly placed, a catheter is advanced which will inject a contrast agent through the ducts. The contrast is visible on X-rays, and allows a physician to evaluate the caliber, length and course of the ducts. An ERCP may be performed if a patient experiences symptoms such as jaundice, abdominal pain, fever or malabsorption.