Among the tumors of all parts of the body, especially the gastrointestinal tract, colorectal cancer is one of the tumors with the best treatment effect. Through standardized multidisciplinary comprehensive treatment, the efficacy can be further improved and a considerable proportion of colorectal cancer patients can be completely cured. Therefore, patients with colorectal cancer must build up confidence and receive standardized treatment in the corresponding specialties. (1) Blood in stool; Rectal cancer often takes blood as the first symptom, so patients with hemorrhoids often have missed or misdiagnosed the disease, which leads to the progress. (2) Change of stool habit; rectal cancer generally manifests as increased frequency of stool, poor defecation, incomplete stool, and feeling of urgency and heaviness; when the tumor causes narrowing of the intestinal cavity, changes such as thinning, deformation, narrowing of stool or grooves on the surface of stool may occur. When the tumor causes narrowing of the intestinal lumen, it may cause changes in stool habit, such as constipation or diarrhea or alternating constipation and diarrhea. (3) Abdominal distension and discomfort; (4) Anemia or emaciation; (5) Abdominal mass is found.