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Urology Health Topics

This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition. Exención de responsabilidad en Español | Complete disclaimer

 

Cystometrogram (CMG)

A cystometrogram allows us to assess how your bladder and sphincter behave while you store urine and when you pass urine. This test is done for people with urinary incontinence, people who have difficulty with urination, and in people with neurologic diseases that can affect bladder function. This test will measure your bladder capacity and pressure. By doing this we can identify problems such as a small capacity bladder, overactive bladder or high pressure bladder.

This test will take about 15-20 minutes. You will be positioned on an exam table lying on your back; or if you use a wheelchair that reclines, the study can be performed while you remain in your wheelchair. Your urethral opening will be cleansed with betadine to eliminate any bacteria on the surface. A catheter with a sensor will be inserted into your urethra and advanced into the bladder. The bladder will be filled with saline solution and filling pressures will be recorded. We will ask you to report any sensations that you might have --coolness from the saline fluid, fullness, the need to urinate, urgency, pain, etc. You may experience some urine leakage during the study. Don’t be embarrassed because this can be expected. If you do have leakage, tell the technician who is doing the test.

You may experience a sense of burning or pressure when the catheter is inserted into the urethra. It is normal to have some irritation when you urinate for 24-48 hours after the study. You may also note a small amount of blood in the urine. You will be given an antibiotic prior to the procedure, to guard against infection.

If you are being seen for urinary retention, we will ask you to empty your bladder at the end of the test. Measuring the bladder pressure during urination will help us identify the problem so that we can prescribe treatment.

You do not have to do anything special to prepare for this study. You can eat and drink as you normally would before you arrive to the clinic. This test is done in the clinic and does not require sedation or anesthesia. You may resume your usual daily activities immediately following the cystometrogram.

Call the clinic nurse if you develop a fever of 100.5 degrees Fahrenheit or higher, have chills, persistent bleeding, or cannot urinate.

Revised by Jerilyn M. Latini, MD , Deborah Crider, NP, Charlene Neer, RN and Dawna D. Allore, RN., May 2006