Gastrointestinal bleeding refers to the condition where blood cells turn black after being decomposed by intestinal bacteria, thus clinically presenting as black stools. Therefore, with a small amount of upper gastrointestinal bleeding, it may simply present as black stools. Of course, with a larger amount of bleeding, it can manifest as vomiting blood or bloody stools, and severe cases may accompany symptoms of low blood flow, such as dizziness, fatigue, chest tightness, etc. For patients with upper gastrointestinal bleeding, it is recommended that they visit the gastroenterology department of a local hospital to undergo further examinations including complete blood count, stool tests, and gastroscopy. Gastroscopy can help identify the location and nature of the bleeding, whether it might be peptic ulcers or gastrointestinal tumors, etc. For treatment, medications that regulate acid and protect the stomach or those that stop bleeding and replenish fluids can be considered symptomatically. Of course, if the black stools are suspected to be caused by a tumor, surgical intervention is generally required.