This procedure looks at the lining of your esophagus, stomach, and duodenum (that's the first part of your small intestine). It's done with an endoscope. That's a special camera that looks like a flexible tube.
To begin, you're given medicine to make you feel relaxed and comfortable. An anesthetic may be sprayed into your mouth. That's so you won't cough or gag when the endoscope is put in. You'll also wear a mouth guard to protect your teeth. You lie on your left side for the exam.
The doctor puts the scope into your mouth. It is guided through your throat, down your esophagus and into your stomach. Air is pumped through the scope to help the doctor see more clearly. The doctor carefully examines the lining of your digestive tract. The scope can reach all the way into the duodenum. The doctor may put instruments through the scope to take a tissue sample. We call that a "biopsy." And, your doctor may be able to treat some small problems (such as a bleeding blood vessel or a polyp) through the endoscope during the procedure.
When the procedure is done, you'll be watched closely for a brief time while the anesthetic wears off. You can't eat or drink until your gag reflex returns, because you could choke. Your healthcare provider will give you tips to help your recovery.