As the old saying goes, disease enters through the mouth. This phrase could not be more accurate in the development of digestive diseases, but it also implies another layer of meaning: proper dietary care is essential for the healing and even restoration of health of digestive diseases. From the point of view of care, diet can be divided into the following categories: 1. Fasting: means not to eat (including water) anything. It is mostly applied to acute pancreatitis, upper gastrointestinal bleeding (vomiting blood, black stool), severe and frequent vomiting, severe diarrhea, pyloric obstruction, intestinal obstruction, etc. 2.Fluid diet: refers to the food that can be eaten in fluid form but does not contain any solid solute, such as water, rice soup, vegetable juice, fish soup, etc. It is mostly applicable to the beginning of resuming diet after the above fast. 3, semi-liquid diet: refers to the food that can be eaten in fluid form and contains a little solid solute, such as thin rice, noodles, sesame paste, lotus root powder, etc. The above-mentioned diseases can gradually recover from a liquid diet to a semi-liquid diet, and indigestion, acute and chronic gastrointestinal inflammatory episodes are also applicable. 4.Soft diet: can eat normally. 5, special diet: refers to the need to restrict certain foods because of certain diseases, such as diabetic diet for diabetic patients; low-fat diet for patients with hypertension, hyperlipidemia, cholecystitis and fatty liver; low-salt diet for patients with hypertension and edema; low-purine diet for patients with hyperuricemia and gout; high-quality low-protein and low-phosphorus diet for patients with renal insufficiency. Generally speaking, we will supplement water, sugar, salt, amino acid, fatty milk, vitamins, electrolytes, trace elements and other nutrients through intravenous infusion when we cannot eat, which is called intravenous nutrition, also called parenteral nutrition. Once the danger period is over, gastrointestinal nutrition should be resumed as soon as possible, because it is convenient, effective and in line with the physiological state, and even in comatose patients, as long as there are no contraindications, nutritional support can be given by means of nasogastric tube.