Black stool is not necessarily a sign of terminal cancer, but only the main manifestation of upper gastrointestinal bleeding. Black stool is clinically known as black stool. Black stool is the result of bleeding in the upper gastrointestinal tract, such as gastric or duodenal ulcers, and the blood is digested by gastric and intestinal juices and turned into black material and excreted from the body, which is known as black stool. Normal people will also have black stools when they eat foods with high iron content, such as pig liver and pig blood, etc. The presence of black stools in cancer patients can only indicate that the patient has upper gastrointestinal bleeding, and cannot indicate that he or she has reached the end of his or her life. Malignant tumors of the stomach, esophagus and other parts of the body, even at a very early stage, may cause the patient to relieve black stools because of bleeding. Some terminal cancer patients suddenly have upper gastrointestinal hemorrhage, resulting in vomiting blood and black stools, which ultimately leads to the patient’s death, and then the black stools are the cause of cancer death, rather than a sign of terminal cancer.