Endoscopic retrograde cholangiopancreatography (ERCP) is a minimally invasive diagnostic and therapeutic procedure that combines endoscopy and fluoroscopy to examine and treat problems in the bile and pancreatic ducts. It involves the insertion of a flexible tube called an endoscope through the mouth, down the esophagus, and into the stomach and duodenum. A contrast dye is then injected into the ducts, and X-ray images are taken to visualize any abnormalities or blockages.