Urodynamic Evaluation

This information will help you prepare for your urodynamic evaluation including what to expect before, during, and after your procedure.

A urodynamic evaluation is a procedure to test the function of your bladder, urinary sphincter, and urethra (see figure).

Your doctor and nurse will use this procedure to see:

  • How well your bladder stores urine.
  • How well your bladder empties urine.
  • If your bladder leaks urine.
  • How well you urinate.

Before Your Procedure

  • Tell your doctor or nurse if you take any bladder medications. You may need to stop taking these medications 2 weeks before your procedure.
  • Your doctor will give you a prescription for an antibiotic. You will need to take the antibiotic on the day of your procedure.
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The Day of Your Procedure

  • Take your antibiotic as prescribed.
  • Do not drink caffeinated liquids such as caffeinated tea, coffee, or soda.
  • Eat a regular breakfast. If your procedure is in the afternoon, you can also eat your usual lunch.
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During Your Procedure

  1. You will change into a hospital gown.
  2. You will lie down on an exam table. Your doctor or nurse will insert a very small tube into your bladder or urinary diversion, if you have one. He or she will put another very small tube into your rectum or stoma. These tubes are connected to others that are attached to a computer.
  3. Your nurse will place 2 sets of electrodes on your body, which will measure the muscle function of your urethra. The electrodes will be placed on your upper leg and on your perineum, close to the anus. The perineum is the area between vagina and anus if you’re female, and between the scrotum and anus if you’re male.
  4. Contrast medium, which is a special liquid that can be seen on x-rays, will begin to flow through the tube into your bladder or urinary diversion. When the tubes are in place, a member of your healthcare team will take x-rays.
  5. While your bladder is being filled with the contrast medium, your nurse will ask you to tell him or her:
    • When you feel that your bladder is full.
    • When you have the urge to urinate.
    • When you have a strong urge to urinate.
  6. Once you have a full bladder and a strong urge to urinate, you will empty your bladder with the tubes still in place. More x-rays will be taken.
  7. You may be asked to strain at certain times while your bladder is filling. This may show urine leakage.
  8. If needed, some of these steps may be repeated during the procedure.
  9. When your procedure is finished, the tubes and electrodes will be removed.


Some patients may also need to have a cystoscopy. This is a procedure to look at the urethra, bladder, and openings to the ureters. During this procedure, your doctor will insert a scope (hollow tube with a tiny light on the end) into your urethra. He or she will look at a monitor that shows the inside of your bladder.

Your doctor will speak with you after your procedure is finished.

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After Your Procedure

  • You will probably have discomfort or slight bleeding when you urinate. Drink a lot of liquids over the next 2 days.
  • You may have a little irritation, a few drops of blood, or both when you empty your bladder over the next 24 hours. This is normal.
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Call Your Doctor or Nurse if You:

  • Have bleeding or discomfort that does not improve within 48 hours after your procedure
  • Have a temperature of 101° F (38.3° C) or higher
  • Cannot urinate
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