Total gastrointestinal nutrition refers to a common means of supplementing energy through peripheral vein or central vein for patients who cannot take food and energy by mouth due to gastrointestinal diseases, and the indications for total gastrointestinal nutrition are as follows: a. Patients with advanced rectal malignant tumors, in which the tumor cells invade other organs in the abdominal cavity and are accompanied by intestinal obstruction, at this time, patients are unable to surgically remove the tumors, and fecal matter formed by oral intake cannot be excreted, and in this case, energy can only be supplemented through intravenous nutrition. In this case, the patient cannot remove the tumor by surgery, and the feces formed by feeding through mouth cannot be excreted, in which case the energy can only be supplemented by intravenous nutrition. Secondly, the patient has total small intestine and colon resection due to mesenteric artery embolism or serious car accident, and the residual intestinal tubes in the abdominal cavity are too short, and the energy cannot be fully absorbed by oral feeding, and it is necessary to supplement the nutrition by vein at this time. Third, 3-5 days after the digestive perforation surgery, the patient’s digestive perforation is not completely healed, the intestinal tube needs to fully rest, and can not eat through the mouth, at this time also need to carry out extra-gastrointestinal nutrition therapy.