High-tech gastroscopy is this procedure widely used to diagnose and treat diseases of the esophagus, stomach and duodenum, it is a technique used to directly examine the system. the patient's upper digestive tract with a small camera mounted at the end of the endoscope. Doctors use the endoscope to diagnose diseases and sometimes, treat digestive tract diseases during the endoscopy. So is gastroscopy painful? What is the effect of gastroscopy?