The symptom expression of bowel cancer is related to the location and clinical stage of the tumor. Bowel cancer generally refers to colorectal cancer, i.e. colorectal cancer. Early colorectal cancer symptoms are not obvious and generally easy to be ignored. The clinical manifestations of colon cancer and rectal cancer are different. With the progress of tumor, rectal cancer can show rectal irritation symptoms, which can be manifested as diarrhea, urgency, and incomplete stool, and the symptoms will become more serious as the tumor volume becomes larger and infiltration depth increases; after the tumor surface breaks down, there can be blood in stool, and when the tumor obviously increases and blocks the intestinal cavity, it will lead to obstruction symptoms, abdominal pain, abdominal distension, thinning stool or difficulty in defecation. Symptoms of colon cancer are closely related to tumor site: due to different anatomical sites and tumor growth characteristics, symptoms of right hemicolectomy mainly include unexplained anemia, weakness, loss of appetite, emaciation, dyspepsia, fever and other symptoms, occasionally abdominal pain; left hemicolectomy mainly shows change of stool habit, sometimes blood in stool, progressive constipation and difficulty in defecation in late stage, and more likely to appear intestinal obstruction. With the spread and metastasis of tumor, late colorectal cancer may invade the surrounding tissues and organs, as well as liver, lung, bone and brain metastasis, and the dysfunction of corresponding tissues and organs may appear. Once the above symptoms occur clinically, one should go to hospital for regular examination and active treatment after diagnosis to avoid delaying the disease.