The dietary considerations of bowel cancer patients in different periods are different. Early stage bowel cancer patients should pay attention to the intake of food containing more coarse fiber in the diet to regulate the stool, such as potato, sweet potato, banana, green vegetables, etc. However, the processing should be meticulous to avoid the food being too coarse to cause irritation to the tumor site. 1.Nutrition should be increased for a period of time before surgery. For example, patients who are thin should be given high-calorie, high-protein and high-vitamin diet so that they can increase their weight in a short period of time as much as possible; patients who are obese should be given high-protein and low-fat diet to store some protein and consume body fat because too much body fat will affect wound healing. Try to eat less residue fluid or semi-liquid food in the days before surgery to reduce residue in the gastrointestinal tract. 2.In the initial period after surgery, nutrition is usually supplied by special means, such as parenteral nutrition support through intravenous, or supplemented with a small amount of enteral nutrition support, and when the patient’s gastrointestinal tract gradually recovers, the amount of enteral nutrition is increased, and parenteral nutrition is gradually reduced until it is stopped. At the same time, gradually resume feeding by mouth, first give a small amount of clear liquid food, then gradually transition to whole liquid food, less residue semi-liquid food, etc., and after a period of time, then transition to soft food or ordinary meal in turn. With the deeper research on postoperative nutrition, more and more experts now believe that not only is there no heart to emphasize fasting after surgery for many diseases, but it is more beneficial to patients’ recovery to start enteral nutrition or early feeding in the early postoperative period, and the time to transition to ordinary meals need not be too long, but this needs to be decided by doctors according to patients’ specific conditions. In terms of food variety, more food rich in high quality protein should be eaten, such as chicken, fish, shrimp and soy products, etc., and more fresh juice as well as more fresh vegetables and fruits should be consumed. 3.During and after radiotherapy, according to the patient’s physical condition, it is generally advisable to have a liquid or semi-liquid diet with foods that nourish yin, produce fluid and benefit qi, supplemented by foods that clear heat and detoxify the body, such as lotus root juice, pear juice, sugar cane juice, water chestnut, loquat, kiwi, winter melon, lettuce, bitter melon and fresh meat. During radiotherapy, you can drink green tea in moderation to reduce radioactive damage. 4.Chemotherapy While killing tumor cells, it also has different degrees of damage to normal tissues, so it is necessary to strengthen nutrition and promote tissue repair. High protein and high vitamin diet such as eggs, milk, fish, lean meat, soybean products, fresh fruits and vegetables should be given, and attention should be paid to increase the color, aroma and taste of food to stimulate the appetite of patients. 5.The diet of advanced bowel cancer patients should pay attention to nutritious foods with less coarse fiber, such as eggs, lean meat, soybean products and fine grains, tender leafy vegetables, etc. It is suggested that patients should drink more honey water to laxative. Patients with bowel cancer should avoid spicy and stimulating foods, such as chili, pepper, ginger, etc. Meanwhile, the diets of bowel cancer patients before, after surgery and after radiotherapy are not the same.