Intermittent catheterization (IC) is the insertion and removal of a catheter several times a day to empty the bladder.
After the bladder empties, a small amount of urine may remain in the bladder. This is referred to as a postvoid residual (PVR).
If the person cannot urinate or empty the bladder completely, the PVR increases and can contribute to UTIs, overflow UI, and permanent damage to the bladder and kidneys.
Research has shown that regular bladder emptying reduces intravesical (in the bladder) pressure and improves blood circulation in the bladder wall, making the bladder mucosa more resistant to infectious bacteria.
By inserting the catheter several times during the day, episodes of bladder overdistention are avoided.
Also, the bladder wall is susceptible to bacteria that circulate in retained urine. When the bladder becomes stretched from retained urine in the bladder, the capillaries become blocked
The key to avoiding UTIs is avoiding high intravesical pressure and overdistention of the bladder, thus preserving adequate blood supply to the bladder wall.