The process of colonoscopy and gastroscopy mainly includes four processes: preparation, choosing the appropriate position, entering and exiting the mirror. 1. Enteroscopy: (1) Preparation: 3 days before the examination, mainly eat semi-liquid food such as thin rice, and the day before the examination, you need to take laxatives to empty the intestine. (2) Choose the appropriate position: try to lie mainly on the left side, and bend both knees. (3) Entering the mirror: the doctor will slowly enter the colonoscope through the anus to observe whether there are lesions in the rectum and colon, if there are lesions, the lesions can be electrically resected or a small portion of the biopsy can be taken for histopathological examination. (4) Withdrawal of the mirror: after the completion of the examination, the enteroscope is slowly withdrawn from the anus. 2. Gastroscopy: (1) Preparation: two days before the examination, mainly eat thin rice, noodles, milk and other easy-to-digest food; the day of the examination needs to be fasted for 6~8 hours. (2) Choose the appropriate position: take the left lateral position for the examination, with both knees slightly flexed. (3) Entering the mirror: the patient is instructed to bite the dental pad tightly, the gastroscope is inserted through the mouth and along the pharynx, and the patient takes a deep breath through the nose to do a swallowing action to cooperate with the examination. The gastroscope then enters the stomach through the esophagus and then reaches the duodenum, completing the examination of the duodenum, stomach and esophagus. (4) Exit: Exit the gastroscope at the end of the examination, and try to inhale to avoid abdominal distension. If you have gastrointestinal discomfort and need to undergo gastroenteroscopy, please go to the hospital immediately and under the operation of the doctor for examination, clarification of the cause of the disease and active treatment.