In addition, it is very likely to cause obstruction and irritation of intestinal tract, etc. There are many prominent clinical manifestations of bowel cancer, so patients need to be more careful. In the early stage of bowel cancer, blood in stool is mainly painless, and the blood is red or bright red, which is very similar to the symptoms of early internal hemorrhoids; in the later stage, blood in stool is mostly dark red, mixed with mucus and blood of stool or pus and blood. Secondly, change of stool habit is a typical manifestation of middle and late stage of intestinal cancer. Because of rectal mass and its secretion, it can produce intestinal irritation symptoms, resulting in frequent bowel movement, incomplete bowel movement, urgency and heaviness, but the discharge is mostly mucus-pus-blood, and the shape of stool has changed at this time, and the stool is getting thinner and thinner. 3.It is very easy to cause obstruction because the cancer infiltrates around the circumference of the intestinal wall, narrowing the intestinal cavity, especially at the junction of rectosigmoid colon, which is mostly a narrow type of hard cancer, and it is very easy to cause obstruction. Patients with advanced rectal cancer will have some systemic cachexia due to long-term chronic consumption of the disease. In addition, unexplained anemia may appear. Patients must pay attention to timely examination and treatment in professional hospitals for unexplained wasting, weakness and loss of appetite. 4. At advanced stage, bowel cancer often invades the surrounding tissues and organs, such as bladder and prostate, causing frequent urination, urgent urination and difficulty in urination. Invasion of presacral plexus can cause pain in sacrococcygeal and lumbar area. Rectal cancer can also metastasize to the liver, causing hepatomegaly, ascites, jaundice, and even malignant fluid.