Urodynamic Testing

What is urodynamic testing?

Urodynamic testing involves a series of diagnostic procedures that assess how the urethra and bladder are functioning, with respect to releasing and storing urine. Generally speaking, urodynamic tests provide precise measurements using sophisticated instruments to assess the bladder’s ability to eliminate urine steadily and completely. The tests help urogynecologists, like Dr. Sargon Bebla, determine if:

  • A patient is experiencing difficulty in starting a urine stream
  • The amount of effort put forth to maintain it
  • The stream is interrupted
  • There is residual urine left in the bladder after voiding

What does it specifically involve?


Dr. Bebla uses an uroflowmeter to measure the amount of urine and how quickly it is removed from the bladder.* It provides a chart identifying changes in urine flow that shows the peak flow rate and the amount of time needed to achieve it. Abnormal test results occur if the bladder muscle is weakened or if there is an obstruction in urine flow.

Post-void Residual

When urinating is completed, there may a small amount of urine left in the bladder. To find out how much is remaining (called a post-void residue) and to measure it, a catheter can be inserted into your bladder.* A post-void residual of more than 200 ml (about half a pint) usually indicates a problem. If 100 ml (about half a cup) remains, additional testing may be indicated.


This test measures the amount of urine a bladder can hold, the amount of pressure that builds up as it stores urine and how full it is when a patient feels an urge to urinate. It involves inserting a catheter into the patient’s bladder to fully drain it. A specialized catheter containing a pressure sensitive tube (cystometer) is then inserted to slowly fill the bladder with a saline solution and to measure pressure. An additional catheter may be inserted into the rectum to measure and record the pressure there as well.* The procedure can be done in our Modesto clinic and is used to identify involuntary bladder contractions.

Leak Point Pressure Measurement

As a patient’s bladder is being filled during the cystometry, it can suddenly contract and force water out without warning. The cystometer records the pressure at the time the leak occurs. The cystometer’s reading indicates the type of bladder problem that a patient has. The procedure is also used to evaluate the sphincter muscles.

Pressure Flow Study

Following the cystometry test, your provider will ask you to empty your bladder so that the catheter can measure the pressures required to urinate.* This study helps to identify obstructions in the bladder outlet that are typical in men with prostate problems. While a bladder outlet obstruction is less common in women, it can occur with a condition such as a fallen bladder or infrequently after surgery for urinary incontinence.


Electromyography is used to measure nerve impulses and muscle activity in the urethral sphincter, with sensors placed on the skin near the urethra and rectum. Occasionally, the sensors are on the urethral or rectal catheter. The recorded patterns of these impulses shows whether the messages sent to the bladder and urethra are coordinated correctly.

Urodynamic testing in Modesto, California

If you are a woman living in Modesto or the surrounding areas, schedule your urodynamics test today. If you have any questions about this evaluation, give us a call at (209) 409-8513. Dr. Bebla can address any queries or concerns that you might have.

<*Individual results may vary; not a guarantee

Search ...

We're happy to answer any questions you may have, feel free to call us at
(209) 409-8513