Enteroscopy is one of the most specific and commonly used means to diagnose lower gastrointestinal diseases. It is one of the commonly used methods to diagnose intestinal diseases, and is widely used for screening and follow-up of tumors and precancerous lesions in the lower gastrointestinal tract. Within 1 day before the examination, you should eat fluids or semi-fluids with no or little slag, such as rice porridge, millet porridge, rotten noodles and other easy-to-digest foods. It is forbidden to eat vegetables, meat, spicy, stimulating and other hard-to-digest food. The day before the examination dinner eat less slag easy to digest fluid or semi-fluid, try not to eat green vegetables or tomatoes, watermelon and other food with slag and seeds. After the examination should not drink alcohol, no endoscopic treatment of colonoscopy does not need to fast for 24 hours, if there is a need to fast for treatment, should not eat spicy and irritating food. Always eat under the guidance of a doctor before colonoscopy to avoid adverse consequences.