1, internal hemorrhoids for the most common cause of blood in the stool, the initial amount of small, hand paper stained blood or dripping blood, for fresh blood, no pus, serious cases can also be ejected blood, not accompanied by pain. 2, anal fissure caused by blood in the stool and internal hemorrhoids are similar, the difference is that the anal fissure with pain, mostly with a history of dry stool. 3, rectal polyps can also cause blood in the stool, usually fresh blood, small amount, and internal hemorrhoids blood in the stool should not be differentiated, can be distinguished from enteroscopy. 4, perianal abscess caused by blood in the stool, for the stool pus blood, more pain, acute onset, can be accompanied by fever. Zhang Chuanju, Anus and Intestinal Department, Anyang Hospital of Traditional Chinese Medicine 5, rectal tumor: blood in stool is often accompanied by mucus, malignant tumors can have changes in bowel habits, increased frequency, falling, stool shape changes, and so on. 6.Upper gastrointestinal bleeding: black stool, tarry stool, mostly with history of ulcer. 7, ulcerative colitis: pus and blood in the stool, more frequent. Bacterial dysentery: acute onset, pus and blood in the stool, and frequent stools.