Bowel cancer patients’ blood in stool is not persistent, most of them have intermittent blood in stool. Blood in stool is mainly caused by rupture and bleeding of tumor surface, so the surface of tumor will be ruptured for a period of time, but the human body has the function of healing, that is, after a period of time, the rupture of the surface of the tumor will be partly healed by itself, and the bleeding can be stopped by itself. Therefore, blood in the stool should be intermittent, or occasionally with blood in the stool, usually not every time when defecating. It may be accompanied by increased frequency of bowel movements, diarrhea, etc. Therefore, when patients find blood in stool, they should do colonoscopy, CT and other related examinations in time.