An Upper endoscopy uses a scope with a light and camera at its end to look inside of the esophagus, stomach and early parts of the small intestine. This procedure is used to determine the cause of gastrointestinal disorders and symptoms including heartburn, Barrett's esophagus, the presence of hiatal hernias, the cause of abdominal pain, unexplained anemia, and the cause of swallowing difficulties, upper GI bleeding, and the presence of tumors or ulcers.