Gastroscopy is an endoscopic examination for identifying the causes of upper abdomen complaints. It is possible to diagnose peptic ulceration, detect the existence of tumour formations, take biopsies for tissue examinations and detect Helicobacter pylori colonization. The examination is performed by using a gastroscope (a flexible probe with optics at the tip and a working channel for taking biopsies) that is entered through the mouth, passed through the oesophagus into the stomach and duodenum. The condition of the mucous membranes of the abovementioned organs can be assessed visually on the basis of the image displayed on the monitor. During the procedure air is passed into the gastrointestinal tract to increase visibility, which is why meteorism may occur after the examination. The procedure is performed in superficial general anesthesia.