Painless blood in the stool, also known as painless blood in the stool, is used to describe the flow of blood from the anus, some of which is mixed with the stool and can be bright red, black, tarry or dark red in color, and is not painful. The main causes are: 1. anal fissure, mostly in men, usually with blood on the hand paper after the stool; 2. internal hemorrhoids, mostly in men, with blood on the hand paper, dripping blood, or in severe cases, ejection of blood during the stool; 3. bacterial dysentery, with pus and blood-like stool, with urgency, sometimes with mucus; 4. amoebic dysentery, with jam-like stool, secreting purulent mucus, often with fever, abdominal distension, and The accompanying symptoms of abdominal pain, the amount of more; 5, schistosomiasis, with a history of exposure to infected areas, long-term chronic diarrhea, pus and blood-like stools; 6, colon cancer, the nature and shape of the stool changes, with mucus pus and blood stools, mostly in the middle-aged and elderly.