Colon cancer and rectal cancer are two different types of malignant tumors with different clinical manifestations, as follows: 1. In colon cancer, patients will experience abdominal pain and change in stool habit, accompanied by symptoms such as intestinal obstruction, hyperactive bowel sounds, anemia, emaciation and weakness, which can be cachectic in severe cases; 2. In rectal cancer, patients will experience rectal irritation symptoms, and tumor rupture will lead to blood in stool. When the tumor invades the prostate and bladder, it can cause urinary tract irritation symptoms. When the tumor invades the sacral nerve, it may cause pain in sacrococcygeal area.