The duration of potassium permanganate sitz bath for anal fissure is usually about 15-20 minutes. Before the sitz bath, the patient should be instructed to empty the stool and bladder and clean the local skin. The environment should be prepared to maintain a constant temperature and humidity in the ward, and attention should be paid to keeping warm in winter to prevent getting cold. The concentration of sitz bath is 1/5000, if the concentration is too high, it can burn the skin, and if the concentration is too low, it cannot achieve the ideal healing effect. The temperature of the sitz bath, the water temperature should be around 40-43 degrees. Note that the water temperature should be tested first before sitting the patient’s buttocks and perineum in the water and soaking for 15-20 minutes. Patients should dry their buttocks and perineum in time, while wearing good clothing and pants. If the wound is accidentally injured, the doctor should be notified immediately and the medicine should be changed in time.