Bladder irrigation is also a type of chemotherapy because of the chemotherapeutic drugs used. Because bladder cancer is confined to the bladder, bladder perfusion chemotherapy is the most common and the main method of treating bladder cancer. By infusing chemotherapy drugs into the bladder, the chemotherapy drugs can be kept inside the bladder and make close contact with the bladder, which can control tumor cells, inhibit division and growth. Bladder perfusion can have side effects because the mucosa of the bladder is very sensitive to chemotherapy drugs. When using bladder perfusion chemotherapy, bladder mucosal damage and hematuria may occur. Some patients find blood in urine after treatment because of chemotherapy-induced mucosal damage. At the same time, there will be bladder irritation symptoms, patients will experience frequent urination, urgent urination, painful urination, discomfort when urinating, frequent urination but no urination comes out, which are bladder irritation symptoms, all of which have clear correlation with chemotherapy. Chemotherapy drugs can also cause bone marrow suppression, resulting in a decrease in white blood cells, platelets and hemoglobin, all of which are related to the chemotherapy drug chosen. If side effects occur, bladder irrigation can be followed by drugs to reduce the reaction, such as hormonal drugs and hemostatic drugs.