The night before the colonoscopy, it is recommended to eat light, easy to digest food, preferably semi-liquid food, such as a variety of porridge, noodles and soups, etc. Do not eat vegetables with leaves and seeds. The dinner of the day before the colonoscopy should be light food, such as millet porridge, rice porridge, noodles, vegetable soup, etc. These foods are semi-liquid food, which can be easily digested and absorbed by the gastrointestinal tract, and will not affect the preparation of the next day’s bowel cleansing. Usually, before performing colonoscopy, patients are required to empty the intestines, such as the application of compound polyethylene glycol electrolyte bulk, mannitol, etc. to promote defecation until the last stool is clear water-like. Therefore consuming semi-liquid food is more favorable for emptying the bowel. It is recommended to strictly follow the doctor’s instructions for the preparation of colonoscopy so as not to affect the results.