After the catheter is left in place, the patient will have the urge to urinate, and at this time, the patient does not need to take the initiative to urinate, and the urine will drain out on its own. In patients who need to undergo prolonged surgery or who suffer from urological diseases before or after surgery, catheters are usually placed in patients due to the difficulty of urinating on their own or for the purpose of postoperative drainage after urological surgeries. Currently commonly used catheters are rubber products. When the catheter is initially placed, the patient will feel the urge to urinate due to the stimulation of the catheter on the urethra, and at this time, without the need for the patient to make urinary movements, the urine will drain through the opening of the anterior portion of the catheter into the urine bag. If the patient develops prolonged lower abdominal pain and fever after the catheter is placed, the patient should report to the doctor for active treatment.