In recent years, the incidence of colorectal cancer has been increasing year by year due to the change of dietary structure of our people, such as more fine grains, less coarse grains, less dietary fiber and high fat diet. As a serious malignant tumor in the digestive system, rectal cancer is easy to be neglected in the early stage, thus losing the chance of complete cure. In fact, rectal cancer will show many symptoms in early stage. This is an important basis for early diagnosis of rectal cancer. If we pay attention to these symptoms, rectal cancer can be detected early. What are the symptoms of early stage of rectal cancer? Some common symptoms are as follows: 1. change in stool habit, increase in frequency or diarrhea, urgency and heaviness. Kang Jingbo, Department of Radiation Oncology, Naval General Hospital 2, change in nature of stool, mucus stool and pus and blood stool, sometimes manifested as a mixture of mucus, pus and blood and feces. 3. Blood in the stool and black stool. Change in the shape of stool, becoming thin and flat. Alternating diarrhea and constipation. 4.Abdominal pain, bloating, indigestion, loss of appetite, etc. 5. Sudden weight loss and loss of body mass. Anemia of unknown cause, etc. The above are some important symptoms of early stage of rectal cancer. I hope you can have some understanding of them. If you encounter the above situation, you should go to hospital for specialist examination as soon as possible.