This procedure allows the doctor to examine the lining of the esophagus, stomach and duodenum (first portion of the small intestine) to locate any abnormalities. During this procedure, a flexible, fiberoptic tube (endoscope) is passed through the mouth and throat into the upper digestive tract.

While a patient is sitting up, the throat is sprayed with a numbing agent. The physician will then assist the patient in swallowing the thin, flexible endoscope. A biopsy specimen may be taken for microscopic examination. No discomfort is felt if biopsies are taken.

Many people do not recall any of the procedure because of the effects of sedation during the procedure.