A flexible tube with a tiny video camera attached (endoscope) is inserted through the mouth into the stomach and small intestine while you are under sedation (medication to make you drowsy). A smaller tube is then moved through the first tube into the bile duct (the tube that connects your gallbladder to your intestines), or the pancreas duct, through which dye is injected and an x-ray is taken to visualise the ducts.

This procedure enables the removal of stones from the ducts without the need for surgery and also allows for the placement of small drainage tubes (stents) to relieve a blockage in the bile ducts.

Possible complications include inflammation of the pancreas in 2-4% of patients, bleeding or perforation of the wall of the intestine.