Urodynamic Testing

In this Article

What are the Benefits?

Urodynamic testing helps the doctor understand what is causing the child’s problem with holding or releasing urine. With this information, the doctor can recommend the right treatment for your child.

How do I Prepare?

For most urodynamic tests, you don’t need to do anything to prepare your child. The doctor may test for a urinary tract infection before the urodynamic test is done. The doctor may give you some instructions about changing how much your child drinks before the test, so the child will have a full bladder when it’s time for the test. If your child takes any kind of medicine (prescription, over the counter, patch, liquid, vitamin, or supplement), talk to the doctor about whether or not to continue giving the medicine before the test.

How is it Done or Administered?

For observations, the doctor may have the child urinate into a special toilet that can measure how much urine comes out and how fast it comes out. This is also called uroflowmetry.

For all other tests, the child will need a catheter. This is a small flexible tube, put into the urethra through the hole the child urinates from. The nurse will wash the genital area or penis with antibacterial soap. The nurse will guide a small catheter into the urethra and then to the bladder, using a lubrication jelly to help the catheter slide in easily. Some children say the catheter feels like a pinch, while some say it is uncomfortable. Others say it makes them feel as if they need to pee.  Counting out loud, pretending to blow out candles, or blowing bubbles may help relieve these feelings. The nurse will tape the catheter to the inside of the child’s leg to hold the catheter in place. It will drain urine out of the bladder. The catheter might also be used to fill the bladder with contrast fluid or water, depending on the test.

For a cystometrogram, these things will happen after the urinary catheter is inserted:

  • The nurse will gently guide a small rectal catheter into the rectum. A lubricating jelly is used to help the catheter slide in easily. The nurse tapes this catheter to the side of the leg and connects the free end of the catheter to a transducer, a device that measures pressure in the belly.
  • The child’s bladder will be slowly filled with contrast fluid or water. The doctor or nurse practitioner may have your child cough or sit up during the test. The nurse watches for any leaking from the bladder. The doctor or nurse practitioner may also take x-rays.
  • If your child is toilet trained, they will be asked to urinate into a special toilet when their bladder is full. If not toilet trained, the test ends when your child urinates on their own.
For ultrasound, the doctor or technician will put gel on your child’s belly near where the bladder is. The doctor will then move a small instrument back and forth on the child’s belly. The instrument makes sound waves that can create a picture of the bladder.

When Will I Know the Results?

For uroflowmetry and cystometry, you will probably find out the results right after the testing is done. For electromyography and imaging, it may take a few days to a week to get the results. Your doctor will tell you when to expect the test results.

What are Follow-up Requirements and Options?

Your doctor will meet with you to talk about a treatment plan or further testing after your child’s test results are available.

What Should I Expect During Recovery?

Urodynamic testing doesn’t usually require recovery time. Most children are fine after testing. Call your doctor if your child has these signs of a urinary tract infection after the testing:

  • Pain or burning when going to the bathroom
  • Fever
  • Frequent urge to urinate
  • Pain in the lower belly area or the lower back
  • Urine that is cloudy, has blood in it, or smells bad

What is Urodynamic Testing?

Urodynamic testing is any test that looks at how well the bladder is holding and emptying urine. The part of the body that manages urine is called the lower urinary tract. It is made up of the bladder and urethra. Problems with the lower urinary tract can have different causes. Urodynamic testing helps the doctor figure out what is causing the problem and how to treat it.

The bladder is a muscular, hollow organ where urine is stored after it leaves the kidneys. It has a tube at the bottom called the urethra (u-REE-thra). Urine goes down this tube to leave the body when a person goes to the bathroom. The muscles in the bladder relax when it’s not time to urinate, and the sphincter (SFINK-ter) muscles near the urethra stay tight to keep the urine in. When it’s time to urinate, the bladder muscles tighten to squeeze the urine out while the sphincters relax to let it out. The goal of urodynamic testing is to understand which part of this process is not working as it should.

The type of urodynamic test the doctor recommends will depend on the child and the problem. Below is a list of urodynamic tests. You will find more information about each test in the section “How is it done or administered?” below.

  • Observation. The doctor make check to see how long it takes to start urinating and how much urine the child has at one time. The doctor may also check to see if the child can stop and start urine midstream.
  • Uroflowmetry (yoo-roh-FLOH-muh-tree). This test measures how much urine comes out and how fast it comes out.
  • Postvoid residual measurement. This test measures how much urine is left in the bladder after the child urinates.
  • Cystometrogram (sis-toe-MEH-trow-gram). This test measures pressure in the bladder, the amount of urine in the bladder, and how well the bladder neck works (part of the bladder that leads to the opening outside the body). During the test, the doctor or nurse may measure any urine that leaks out and look at how much pressure was in the bladder when the urine leaked. The doctor may also look at how much pressure is needed before urinating can begin and how quickly the urine comes out.
  • Electromyography (ih-lek-troe-my-OG-ruh-fee). When muscles and nerves are active, they create electrical activity. This test uses special sensors to measure the activity of the muscles and nerves in the bladder.
  •  Imaging. Sometimes ultrasound or X-ray is used to see how the bladder fills and empties. With ultrasound, the bladder is filled with liquid and then the doctor moves the instrument along the skin over where the bladder is. Ultrasound uses sound waves to make a picture of the bladder. With x-ray, also called video cystometrogram, the doctor will first put a contrast dye in the bladder so it shows up on the x-ray

What are the Risks and/or Side Effects?

Some urodynamic tests use a catheter, a small tube that goes through the urethra and into the bladder. Your child may feel mild discomfort (stinging) during urination for a few hours after the test. This should last only a day and is normal. Encourage your child to drink plenty of fluids. If they has discomfort when urinating, it may be helpful to allow your child to urinate while sitting in a tub of warm water. Placing a clean, warm, wet washcloth over the urethral opening could also help.

If the stinging lasts more than a few days or gets worse, call your child’s doctor. Urinary catheters can sometimes cause :

  • Urinary tract infection or kidney infection if the catheter brings bacteria into the urethra and bladder
  • Allergy or sensitivity, if the child is allergic or sensitive to latex
  • (Rarely) damage to the urethra, bladder, or rectum when the catheter gets put in