Upper Gastrointestinal endoscopy is a procedure that uses a lighted, flexible camera called endoscope to see the inside of the upper GI tract. The upper GI tract included esophagus ,stomach, duodenum(first part of the small intestine). Upper Gi endoscopy can be used to determine the cause of abdominal pain, nausea, vomiting, swallowing difficulties, gastric reflux, unexplained weight loss, anemia and bleeding. Generally, no eating or drinking is allowed for 4 to 8 hours before this procedure. Smoking and chewing gum are also prohibited during this time. .