Postoperative care after endoscopic submucosal dissection includes the following aspects: 1. Diet is demanding, and generally fasting or a full liquid diet should be observed for 24-36 hours, judging by the circumstances of the procedure and the patient’s own reaction; 2. Pay attention to the possibility of secondary perforation or bleeding. If the bleeding is in the upper segment there will be vomiting blood, and in the lower segment observe whether there is black stool or blood in the stool, such as pulling bright red blood then there is more bleeding. If discomfort or pain is more obvious and involves the whole abdomen, be alert to the risk of perforation; 3. Pay attention to the possibility of subcutaneous emphysema and pneumothorax.