Gastrointestinal complications: 1. Nausea and vomiting: There are many causes of nausea and vomiting, mainly fluid food injected too fast and too much, high osmotic pressure of nutrition solution leading to intolerable pairs, high fat proportion content in nutrition solution, unpleasant smell of nutrition solution, etc. Among them, gastric emptying disorder is the most important cause of nausea and vomiting. During the care, attention should be paid to the concentration, speed, volume and temperature of the gastrointestinal nutrition solution infusion, which should follow the principles of low to high, from less to more, increase the volume first and then increase the concentration, the speed from slow to fast, and the nutrition solution preheating to about 37 ℃ is appropriate to reduce the stimulation of the gastrointestinal tract. If nausea and vomiting are suspected to be caused by gastric emptying disorder, anesthetic drugs should be stopped and replaced with low-fat preparations, keeping the nutrition solution at room temperature, reducing the infusion speed of nutrition solution, and applying gastrodynamic drugs. 2.Diarrhea: Diarrhea is the most common complication in enteral nutrition support, and the incidence can be as high as 62%. Some patients stop using nutrition because of diarrhea, and serious cases may have dehydration, renal failure, or even coma and death. In general, diarrhea is considered to be diarrhea when the daily stool output is >500ml or the number of bowel movements is >3 times a day for more than 2 consecutive days. The causes of diarrhea can be divided into three factors: nutrient solution, patient and improper feeding, specifically: (1), changes in the systemic condition or lactase deficiency, which affects the intestinal absorption capacity of the body. (2), Infectious diarrhea caused by contaminated infusion links, or diarrhea caused by large amounts of broad-spectrum antibiotics, which cause dysbiosis of intestinal flora and are easily complicated by intestinal fungal infections. (3), abnormalities of intestinal absorption and secretion functions. (4), excessive fat in the fluid causes steatorrhea. (5), patient hypoalbuminemia can also lead to the occurrence of diarrhea, etc. To prevent the occurrence of diarrhea, the concentration of gastrointestinal nutrition solution should be adjusted at any time to change the osmotic pressure of the nutrition solution and facilitate intestinal adaptation. Choose a lactose-free nutrition solution and give the patient oral pancreatic enzymes, which can prevent diarrhea caused by lack of lactase and lipase. Correcting hypoalbuminemia and increasing the absorptive capacity of the villi can reduce the occurrence of diarrhea. Once diarrhea occurs, the cause of diarrhea should be identified and treated accordingly. If diarrhea is severe, enteral nutrition should be temporarily stopped and parenteral nutrition support should be used instead. 3, abdominal distension and intestinal cramps: abdominal distension and intestinal cramps are common complications of enteral nutrition. Intestinal cramps, abdominal pain and abdominal distension can occur when the infusion speed is too fast, the temperature of nutrition solution is too low and high osmotic pressure. When the above symptoms appear, first of all, we should identify whether the patient has mechanical or paralytic intestinal obstruction, if there is intestinal obstruction, enteral nutrition should be stopped in time. If the patient’s condition permits, enteral nutrition with more dietary fiber should be used as much as possible, and if necessary, gastrointestinal motility drugs or enemas should be applied to improve the occurrence of abdominal distension.