The life expectancy of middle and late stage rectal cancer is related to the general condition of patients, disease stage, whether to treat or not, treatment effect and tumor cell differentiation degree, etc., which cannot be generalized. The prognosis of patients with mid- to late-stage rectal cancer is affected by many factors. Patients with good general health condition, good differentiation of tumor cells, timely treatment and good efficacy have relatively good prognosis, which is usually expressed by 5-year survival rate, such as five-year survival rate of 80% for stage II; 5-year survival rate of 40% for stage III; however, 5-year survival rate of stage IV is low, and if multiple metastases and general condition are poor, the survival period of patients can hardly exceed 1 year. Enhancing the immunity of cancer patients can slow down the progress of tumor. It is recommended to reduce the intake of fatty foods, prohibit spicy and stimulating, hot and dry foods, and take appropriate drugs for kidney and spleen to improve the body’s ability to resist diseases.