There are no obvious symptoms in the early stage of rectal cancer, and symptoms appear only when the lesion affects defecation or breaks down or bleeds. Typical symptoms include change of defecation habit and change of stool trait, etc. If patients find that there are such conditions in the near future, they should actively seek medical treatment for timely investigation, so as to achieve early detection and early treatment, which is beneficial to treatment and disease control. 1. Change of defecation habit: When tumor stimulates rectum and produces rectal irritation sign, patients may have change of defecation habit, such as increase or decrease of stool frequency, or constipation, which usually requires reference to previous defecation condition. The method of differentiation usually needs to refer to the past defecation situation. At the same time, the patient may have the feeling of incomplete defecation, i.e. the feeling of urgency and heaviness. 2. change of stool characteristics: when the tumor causes narrowing of the intestinal lumen, the stool may become thin, and it may also be accompanied by obstruction symptoms, such as abdominal pain, abdominal distension and hyperactive bowel sounds. There may be blood on the stool surface after tumor rupture and bleeding, or it may be mucus stool, pus and blood stool, etc. If the lesion invades the surrounding tissues or metastases, corresponding symptoms may appear, such as frequent urination, hematuria, abnormal vaginal discharge, sacrococcygeal pain, enlarged inguinal lymph nodes, etc. Some of the above symptoms are not specific, so further examination and differentiation are needed. The prognosis of rectal cancer is better after early active treatment, so patients should not relax their vigilance when abnormal manifestations occur and should not miss the time of treatment.