In general, after small and medium-sized surgeries, the diet does not need to be strictly limited. After larger surgeries, especially esophageal and gastrointestinal surgery, the timing of eating and the type of diet depend on the nature of the lesion and the way the surgery was performed. Due to the effects of surgical trauma, anesthesia and analgesic drugs, the patient’s appetite decreases for a short period of time after surgery. In addition, it takes 24-48 hours to recover the peristaltic function of the gastrointestinal tract after abdominal surgery, and the patient can start eating only after he has normal exhaustion and defecation. The principle of oral diet is to start with fluid that can be easily digested and absorbed, gradually transition to semi-liquid, and finally return to normal general diet. The essentials diet has been widely used clinically, which provides sufficient calories and protein and is a more ideal diet before and after gastrointestinal surgery. Severe external gastrointestinal fistula and complex surgery of major organs have more stringent nutritional requirements, and complete extra-gastrointestinal nutrition can be implemented from 5 to 7 days before surgery to provide sufficient heat and nitrogen sources to meet the needs of positive nitrogen balance of patients. The first 2 days after non-gastrointestinal surgery, it is best to eat a light liquid or semi-liquid diet, such as thin rice, noodle soup, etc. It is not easy to eat gas-producing foods, such as milk, beans and overly sweet diet. On the 3rd to 4th day after the anal discharge, you can start to eat highly nutritious semi-liquid food, such as chicken soup, egg custard, milk, noodles, etc. On the 5th to 7th day, you can enter the general diet. When you start to eat after gastrointestinal surgery, you should eat liquid food with reasonable combination to ensure the intake of protein, fat, vitamins and other nutrients, such as egg soup, juice, etc. It is not easy to eat gas-producing food, so you can gradually enter semi-liquid diet, and later you can gradually choose the diet according to the individual situation and pay attention to ensure nutrition. 6 meals per day for liquid food, 4 meals per day for semi-liquid food and 3 meals per day for general food. Do not eat too much to avoid abdominal distension.