1~2 days before the colonoscopy, it is recommended to eat some light, easy to digest fluid or semi-fluid diet, as little or no slag, such as millet porridge, egg custard, etc., and fast on the day of the examination. Enteroscopy is an inspection method that inserts the enteroscope through the anus along the intestinal lumen to the ileocecal part to observe the lesions of the colonic mucosa, and if necessary, it is a good idea to take a biopsy of the suspected part for pathological examination, which is the first choice for checking the intestinal tumors and precancerous lesions. Before the colonoscopy, it is necessary to prepare the intestinal tract according to the doctor’s instruction. One day before the examination, the diet should pay attention to as little slag or no slag as possible, and take the light, easy-to-digest fluid or semi-liquid diet as the main, such as millet porridge, egg custard, rotten noodles, milk and so on. When eating, pay attention to chewing and swallowing slowly, try to chew the food completely before swallowing. Patients should avoid eating foods rich in dietary fiber (such as celery, dragon fruit, coarse grains, etc.) and hard-to-digest meats, fried foods, etc., to avoid producing a large amount of feces in the intestinal lumen, which will affect the examination results. Enteroscopy requires fasting for 6~8 hours before the examination, therefore, you should fast on the morning of the examination. At the same time, take laxatives such as polyethylene glycol as prescribed by the doctor to promote the discharge of feces in the intestinal tract, so that the intestinal tract will be in a clean state, which is convenient for the doctor to make observation.