Gastrointestinal bleeding in children can occur at any age, manifested as vomiting blood, blood in the stool, or both. The causes of bleeding are complex. In addition to diseases of the digestive tract itself, it may also be a local manifestation of systemic diseases. The site of bleeding can be the upper digestive tract or the lower digestive tract. Upper gastrointestinal bleeding refers to bleeding caused by lesions of the digestive tract above the Treitz ligament, such as the esophagus, stomach, posterior duodenum, pancreas, gallbladder, etc.; lower gastrointestinal bleeding refers to bleeding in the digestive tract below the Treitz ligament, such as the small intestine, colon, rectum, and anus. Children have poor tolerance to blood loss, and clinical symptoms vary in severity. Some have large amounts of bleeding and rapid bleeding, which may lead to fatal hemorrhagic shock, while others have no obvious clinical symptoms and only show positive occult blood in the stool. Repeated small amounts of bleeding can lead to anemia in children over time, and correct diagnosis and treatment must be made in a timely manner. Although the current diagnostic methods have been greatly improved and the understanding of the pathophysiology of hypovolemic shock has made great progress, the diagnosis and treatment of pediatric gastrointestinal bleeding still needs further research. Gastrointestinal bleeding in children is not uncommon in clinical practice. In terms of body weight and circulating blood volume, the risk of bleeding in children is greater than that in adults. Therefore, quickly determining the cause and location of bleeding and timely treatment are of great significance to prognosis.