Stress ulcers are acute gastric mucosal lesions that occur in cases of severe stress such as multiple trauma, severe systemic infection, massive burns, shock, and multi-organ failure, and are one of the common causes of upper gastrointestinal bleeding. The lesions of stress ulcers have 4 major characteristics: 1. they are acute lesions, arising in stressful situations; 2. they are multiple; 3. they are scattered in the acid-secreting parts of the gastric body and the mural cells of the gastric fundus, and are rare in the gastric sinus; 4. they are not accompanied by high gastric acid secretion. Most of the patients in the pediatric surgical intensive care unit are children after medium to major surgery, while there are some inoperable preoperative patients. These patients are in serious condition, and the surgery is traumatic for small infants, so the possibility of stress ulcers in children in the intensive care unit is high. The likelihood of ulcers is even greater if the child is combined with shock, severe infection, hypoxia, and organ failure. Once a patient has upper gastrointestinal bleeding, the first thing to consider is the possibility of stress ulcer due to stress ulcers, which should be dealt with promptly. 1.For children with more intraoperative bleeding, timely supplementation of red blood cell suspension to correct anemia, routine postoperative preventive application of proton pump inhibitor to protect gastric mucosa, and hemostatic combination to prevent hemostasis. 2.Negative pressure suction with gastric tube Continuous suction with an indwelling gastric tube can prevent gastric dilatation and remove gastric acid and blood accumulation in the stomach to understand the bleeding situation. 3.Ice saline or vasoconstrictor gastric lavage Ice saline lavage or vasoconstrictor drip can make mucosal vasoconstriction to achieve hemostasis. 4.For stress ulcers with hemorrhage, consider surgical treatment when medical treatment is ineffective. In addition to the above treatment measures, the following treatment measures should also be done: 1. The child should absolutely rest in bed, and small infants should be given appropriate analgesic sedation. 2. Closely monitor vital signs, establish 2 infusion channels, give urinary catheterization, and prepare blood. 3.Fast. 4.Accurately record the amount, color, nature and bleeding time of blood vomiting and blood in stool, and keep the specimen for testing. Make a good record of 24-hour in and out volume. 5.Closely observe the bleeding symptoms. If the patient has pale face, cold sweat, irritability, fine and rapid pulse, blood pressure drop and other shock symptoms, give anti-shock treatment such as lying down, oxygen absorption and rapid infusion quickly.