Blood in stool caused by bowel cancer may be bright red, dark red or black, which is mainly based on the location of bowel cancer, that is, the distance from the anus, and also needs to be combined with the amount of bleeding to make a common judgment, as follows: 1. Close to the patient’s anus: when bleeding, it usually appears as bright red blood stool or dark red blood stool; 2. Far from the anus: it usually may be black stool. If the patient has a very large amount of bleeding inside the intestine, it may also appear as dark bloody stools or soy sauce colored stools. For patients with less bleeding, most of them appear as black stools. Whether the patient has black stools or bloody stools, it is recommended that the patient go to the hospital for a colonoscopy in a timely manner.