Patient should inform the physician of any disease or conditions that they have such as allergies, asthma, heart disease, and history of allergies to specific medicine and seafood.

Physician will administer medication to let the patient sleep during the exam so that the patient does feel any pain.

Once the patient is asleep, the physician inserts a flexible endoscope into the patient' s esophagus, stomach, and duodenum until it reaches the spot where the ducts of the biliary tree and pancreas open into the duodenum. Then a special contrast medium is injected in order to check for the narrowing of ducts and presence of gallstones. The physician is able to insert an instrument into the endoscope and remove the gallstone or relieve the obstruction.