Endoscopy means examining the body cavities with a camera and is used in many diagnosis and treatment methods in the medical field. In gastroscopy, the oesophagus, stomach and duodenum are examined through the mouth. The procedure is performed under sedation, that is, in a state of light sleep, and is easily performed without the patient feeling anything. A piece of the stomach can be taken during the procedure. Polyps can be removed. Both diagnosis and treatment are performed at the same time.