The clinical manifestations of gastrointestinal bleeding depend on the amount, speed, location and nature of the bleeding, and are also related to the patient’s age and the compensatory capacity of the circulatory function. Vomiting blood and black stools are characteristic manifestations of upper gastrointestinal bleeding. Large amounts of bleeding are followed by the appearance of black stools; if the amount of bleeding is relatively small, there may be no vomiting of blood. Second, bloody stools and dark red stools are mostly the clinical manifestations of lower and middle gastrointestinal bleeding. Third, hemorrhagic peripheral circulation failure, a large amount of acute blood loss, due to the rapid reduction of blood volume in the circulation, resulting in peripheral circulation failure, manifested as dizziness, panic, etc. Fourth, anemia and changes in blood picture, all have hemorrhagic anemia after acute massive bleeding. V. Fever, which occurs in some patients within 24 hours after gastrointestinal hemorrhage and continues to normalize after 3-5 days. Sixth, azotemia, after a large amount of blood protein is absorbed by the digestive tract, the level of urea nitrogen in the blood may appear transiently elevated, called enterogenic azotemia.