The color of blood in the stool varies, as do the symptoms of the disease. The color of blood in stool can be classified as bright red, dark red or blackish purple. If the amount of blood in stool is relatively small and does not cause a change in stool color, an occult blood test needs to be performed at the hospital to determine if it is occult blood. If the color of the blood in the stool is bright red, it means that the affected area is close to the anus, mostly due to hemorrhoids, and a few due to tumors. Consider bleeding from gastroduodenal ulcer, stomach cancer, intestinal polyps, anal canal, rectum and other lesions, bile duct stones, bile duct cancer and other pancreatic diseases. Vascular diseases of the small intestine acute bacterial dysentery, amoebic dysentery can cause black purple blood in the stool, when the symptoms of blood in the stool must go to the hospital to do colonoscopy, early diagnosis and early treatment.