What is upper endoscopy?
Upper endoscopy lets your doctor examine the lining of the upper part of your gastrointestinal tract, which includes the esophagus, stomach and duodenum (first portion of the small intestine). Your doctor will use a thin, flexible tube called an endoscope, which has its own lens and light source, and will view the images on a video monitor. You might hear your doctor or other medical staff refer to upper endoscopy as upper GI endoscopy, esophagogastroduodenoscopy (EGD) or panendoscopy.
What happens during upper endoscopy?
Your doctor might start by spraying your throat with a local anesthetic or by giving you a sedative to help you relax. You'll then lie on your side, and your doctor will pass the endoscope through your mouth and into the esophagus, stomach and duodenum. The endoscope doesn't interfere with your breathing, most patients consider the test only slightly uncomfortable, and many patients fall asleep during the procedure.
What preparations are required?
An empty stomach allows for the best and safest examination, so you should have nothing to eat or drink, including water, for approximately six hours before the examination. Your doctor will tell you when to start fasting as the timing can vary.
From the American Gastroenterological Association
References: ASGE, American Society of Gastrointestinal Endoscopy