The early symptoms of rectal cancer are not very obvious. About 85% of patients with early rectal cancer whose cancer is confined to the rectal mucosa have blood as the only early symptom, but this symptom is often not taken seriously by patients and delays the treatment time. In addition, early symptoms of rectal cancer are often manifested as increased number of bowel movements, incomplete bowel movements, frequent bowel movements, and change of bowel habits such as urgency and heaviness. The early symptoms of rectal cancer are as follows: 1. change of bowel habit Early stage of rectal cancer often has the symptoms of change of bowel habit, which are mostly manifested as diarrhea or constipation, incomplete bowel movement, progressive thinning of stool, and in late stage, there is the phenomenon of urgency and heaviness. 2.Pain Symptoms Early abdominal pain symptoms of rectal cancer are not very common, but patients with mid to late stage rectal cancer may have pain or painful urination due to the invasion of tumor tissues into surrounding organs, including the prostate or invasion of the surrounding sacrum, and we should be alert to the problem of rectal cancer at this time. 3.Stressful defecation In the early stage of rectal cancer, there will be stressful defecation, and the discharged stool will have pressure marks and be in the shape of grooved flat strip or thin strip. 4.Blood in stool Blood in stool is one of the most common early symptoms of rectal cancer, which shows that early bleeding is small and can be seen on the surface of stool, but if combined with infection, it can show as thick blood in stool. Therefore, if the above symptoms occur, special attention should be paid to them and it is recommended to go to regular hospitals for corresponding examination and clear diagnosis to avoid delaying the disease.