Enteroscopy (endoscopic gastroduodenoscopy) is a modern, low-traumatic method of examining the upper gastrointestinal tract using a thin flexible optical endoscope probe inserted into the esophagus and stomach through the mouth, and, if necessary, into the small intestine. If the patient is diagnosed with peptic ulcer, this control method becomes necessary. However, many patients complain of feeling nausea, stomach pain, heartburn and even vomiting when they see an endoscope. That is why the decision to conduct an endoscopic examination is made in each specific case by the doctor, taking into account the severity and frequency of relapses of the disease of the stomach and duodenum