When there is difficulty in urination or surgery, you need to cooperate with the use of catheterization to connect the urine bag to the body, there are three connection methods: connection through the external urethra, cystostomy and nephrostomy. 1, connection through the external urethra: is the most commonly used way to solve urinary retention, if it is a female patient, the urethra can be inserted 3-7cm into the bladder, men about 10cm into the bladder, and then connect the urine bag, you can put urine to drain out; 2. Cystostomy: an incision of about 1cm needs to be made on the pubic bone, the layers are cut in turn, and a special puncture device is used to puncture from the skin into the bladder, access the ureter, and then connect the urine bag, which can solve the problem of not being able to urinate through the urethra; 3. Renal puncture fistula: the urine bag is connected to the body to solve the problem of the upper urinary tract, mainly hydronephrosis. If the hydronephrosis is not able to place an internal stent and needs to be drained by means of a stent tube placed in the ureter, a nephrostomy can be considered outside the body and then a urinary catheter can be left in place for treatment. These three ways of connecting the urine bag, it is recommended that the urinary catheter be changed once a month and the bag be changed weekly. If available, try to opt for the placement of an anti-reflux urine bag. The urinary catheter and body connection is also disinfected using iodophor. Patients are advised to drink as much water as their physical condition allows to keep their urine flowing smoothly, and if necessary, anti-inflammatory medications can also be added under medical supervision to prevent infection.