Blood in the stool is the most common symptom of early rectal cancer. Rectal cancer is a common malignant tumor of the digestive tract. Early rectal cancer refers to the tumor lesions are limited to the intramucosa or submucosa layer, without exceeding the muscle layer of intestinal wall. The main manifestations of patients in this period are mainly blood in stool and change of bowel habit. Among them, blood in stool can occur in 80-90% of early rectal cancer patients. The amount of blood in stool may be large or small, and the color is mostly bright red or dark red. Because the manifestation of blood in stool is often similar to hemorrhoids, it is often necessary to distinguish it from hemorrhoids in clinical work. Some patients will also have a change in bowel habits, manifested in increased frequency of defecation, change in fecal character, there will also be mucus manifestations. A few patients will have the sensation of anus falling down before defecation, and have the sensation of urgency and heaviness after defecation. Blood in stool is a common symptom in early stage of rectal cancer. Therefore, patients need to go to regular hospitals for consultation in time after bloody stools appear, follow the diagnosis and treatment advice of specialists, standardize the treatment and have regular follow-ups.