Filling cystometry and pressure flow study are part of Urodynamic testing (sometimes referred to as UDS). These bladder function studies help diagnose problems related to urine control (or urinary incontinence), difficulty emptying the bladder, urgent or frequent need to urinate, weak or intermittent urinary stream and recurrent urinary tract infections.
Generally, there is no preparation necessary for this testing. However, sometimes you may be asked to stop taking certain medications in advance.
Before the testing you will be asked to empty your bladder as best you can. A small soft tube (called a catheter) is inserted into the urethra until it reaches the bladder. The catheter allows the bladder to be emptied completely (measuring the amount remaining in the bladder after urination known as residual urine) and then to measure the pressures in the bladder. Another small catheter is also placed into the rectum. This catheter allows us to estimate the pressure on the outside of the bladder in the abdomen. The bladder is then slowly filled with liquid (usually sterile water, sterile saline or a sterile fluid that can be seen on x-ray). You will be asked to describe sensations that you feel in your bladder. You may be asked to cough or bear down to look for any leakage.
When you feel that your bladder is full and you have a strong urge to urinate, you will be asked to urinate into a special commode chair. You will be asked to urinate with the special catheters in place. This allows your health care provider to look at pressure and volume measurements and bladder function as you urinate.
After the studies you may experience some burning, urinary frequency and/or urgency. You may also have some pink color in the urine. If discomfort persists, fever develops or urine appears bright red, a physician should be notified.