Rectal radiotherapy, like radiotherapy in other areas, is painful because while killing tumor cells, the rays also damage the surrounding normal tissues. Common manifestations are usually symptoms of the digestive system, including nausea, vomiting, abdominal pain, diarrhea, especially diarrhea is more common. The blood picture is often referred to as white blood cells and platelets, sometimes the white blood cells and platelets are low, and sometimes chemotherapy is given at the same time as radiation therapy, the reaction may be slightly heavier, once the white blood cells and platelets are lowered, symptomatic treatment is needed. Local symptoms include the patient feeling distension and pain in the perineum and a feeling of falling, etc. These are edema reactions caused by radiotherapy, which can be treated symptomatically. There are also symptoms of bladder irritation, sometimes such as frequent urination. If infection is ruled out, symptomatic treatment can be given, and if infection is indeed present, anti-inflammatory treatment should be given. Skin reactions are localized skin erosions, ulcers, and even small ulcers, which can usually be treated symptomatically. Patients are advised to tell the doctor at the first sign of a reaction, and early treatment is required to minimize the reaction as much as possible.