There are more than five complicated symptoms in early stage of rectal cancer, and the more typical ones are blood in stool, abnormal stool, malnutrition and so on. 1. Blood in stool, after the tumor is stimulated by food, it will ulcerate and bleed, thus causing blood in stool and pus and blood in stool. 2. Abnormal stools, when cancer cells stimulate the rectum, patients will have more frequent stools, thinner stools or stool grooves, and some patients with more serious conditions will also have abdominal pain and bloating. 3. Malnutrition, rectal cancer belongs to consumptive disease, plus the presence of tumor will affect the absorption of food, so it will cause body wasting, anemia and other malnutrition phenomena. In addition, patients may also have anal swelling, intestinal obstruction, abdominal pain, etc. If the above symptoms occur, it is recommended to consult the doctor in time, make a clear diagnosis and actively cooperate with the treatment.