Gastroscopy is mainly used for the observation and treatment of the esophagus, stomach and duodenal bulb, and is the most commonly used and accurate method for diagnosing upper gastrointestinal diseases, and has been widely used in clinical practice. Gastroscopy before the need to fast for more than 6 hours, such as gastric outflow tract obstruction, need to fast for 2 ~ 3 days, gastroscopy the night before dinner normal diet, the day of the examination after the morning fasting, to maintain a fasting state, severe and weak should be rehydrated before the operation, before the examination, relaxing the belt, remove the glasses and movable denture. In order to avoid nausea caused by reflex, vomiting and other discomforts, gastroscopy before the need for oral local anesthesia drugs, such as bupivacaine, oxybuprocaine and so on. Oral antifoaming agents such as dimethylsilicone oil, simethicone oil, etc. can also be taken to obtain a clear vision during gastroscopy and shorten the time of endoscopy. Two or three days before the colonoscopy should eat a diet with little residue, the day before the examination, eat a liquid diet, start fasting 8 hours before the examination, keep an empty stomach, and those who are intolerant to hunger can drink sugar water. If painless colonoscopy is needed, 4 hours before the operation should be fasting water, in accordance with the required time and dose, take bowel cleansing medication, and drink a sufficient amount of fluids in accordance with the requirements of the discharge of yellowish transparent watery stools shall prevail.