Eat as few vegetables as possible before the colonoscopy, if you must eat can eat a small amount of winter melon, potatoes, cucumbers and other vegetables with less dietary fiber. Two to three days before the colonoscopy should be prohibited from eating food containing crude fiber, pay attention to the cooking method should be light, should not be fried, stir-fried and other ways of cooking, and should not be used chili peppers, peppers and other condiments for seasoning, in order to avoid stimulation of the gastrointestinal mucosa; should not be consumed at once, so as not to aggravate the burden on the gastrointestinal, affecting the effect of gastrointestinal tract cleansing before the colonoscopy. It is best to eat fluids or semi-fluids before the colonoscopy, low residue diet, such as noodles, millet porridge, milk, mashed bananas, etc. It is not advisable to eat dietary fiber-rich fruits and vegetables, such as oranges, apples, celery, leeks, etc. two days before the examination. Fasting on the day of examination. Iron medicines should be stopped 3 days before the colonoscopy, and polyethylene glycol laxative should be taken orally 3 hours before the examination to clean the intestines. Enteroscopy should be performed under the guidance of a doctor and follow the doctor’s instructions.