Gastroscopy or upper gastrointestinal endoscopy is a procedure of examining the condition of the esophagus, stomach, and duodenum using a scanner called an endoscope, which is a thin and flexible tube equipped with lights and cameras. Gastroscopy is generally used for the purpose of examining and diagnosing symptoms experienced by patients, such as indigestion, recurrent heartburn, pain in the upper abdomen, excessive nausea and vomiting, or difficulty swallowing. This procedure can also be used as a tool to treat certain conditions, such as bleeding in the stomach ulcer and gastric inflammation, and removing polyps or tumors. Gastroscopy indications and contraindications Specifically, the following are conditions that can be seen during a gastroscopy: Gastritis or inflammation of the stomach. Gastric ulcer. Duodenal ulcer. Gastroesophageal reflux disease (GERD), which is a leak in the stomach that causes stomach acid to rise into the esophagus. Celiac disease, which is a di