The occurrence of blood in the stool of rectal cancer patients is not regular. The occurrence of blood in the stool is mainly related to factors such as whether the rectal tumor breaks down and the defecation situation. If the patient’s stool can maintain a relatively thin and soft state, the blood in stool is relatively mild. However, if the stool is dry, the surface of the tumor may be repeatedly irritated, causing the tumor to break down, and blood in the stool may occur repeatedly. Such patients will sometimes have bright red color and sometimes dark red color when they have blood in stool. In addition, some rectal cancer patients have normal stool color from the appearance observation, but anemia can be found during physical examination, and further examination can find positive fecal occult blood in stool routine and occult blood test. In addition, since the symptoms of rectal cancer patients with blood in stool do not have obvious regularity, if blood in stool occurs in daily life and the amount of blood in stool is large or the symptoms of blood in stool persist without relief, you must be alert and go to gastroenterology or colorectal surgery for consultation in time.