Blood in the stool for a day and then no more, consider the occurrence of blood in the stool, can be caused by hemorrhoids, anal fissure, intestinal occupation, ulcerative colitis and other diseases. 1. Hemorrhoids: Hemorrhoidal blood in the stool is mainly bright red in color, often attached to the surface of the stool rather than mixed in the feces, but also before and after the bowel movements of blood. 2. Anal fissure: anal fissure can appear the symptom of blood in stool, usually less, but also in defecation with severe pain symptoms, defecation is slightly relieved, and then there can be the performance of severe anal pain. 3. Intestinal space occupation: intestinal polyps and tumors and other space-occupying lesions, may appear with blood in stool, may be accompanied by abdominal pain, anemia and other symptoms, but also due to intestinal blockage, intestinal lumen narrowing the performance of defecation difficulties. 4. Ulcerative colitis: ulcerative colitis can appear mucus, pus and blood in the stool, accompanied by abdominal pain, acute and severe symptoms, in addition to different degrees of systemic symptoms. Blood in the stool for a day and then no more, need to consult a doctor in time, by a specialist doctor to clarify the cause of blood in the stool and the condition, and actively give treatment, will help the early control of the disease cure.