Urine is then held in the bladder, which is like a muscular bag, by a strong circular muscle band called a sphincter muscle. When the brain sends a message to relax the sphincter muscle, the urine is released and flows down the urethra and out of the body. If the bladder cannot contract when the brain tells it to empty, then it will become overfilled. An overfilled bladder may damage the kidneys because of the pressure generated by the large amount of urine. The bladder may overfill with urine and become distended.
Catheterization keeps the bladder from leaking when it is distended or overfilled.
It is believed that most urinary tract infections are caused by incomplete emptying of the bladder. In some cases, damage to the kidneys may result. With regular, complete emptying of the bladder, bacterial growth can be prevented and your child s kidneys and bladder can be protected from infection and disease. Sometimes medications are prescribed to help your child stay dry while he or she follows a catheterization program. These medications might cause tightening of the bladder neck in order to hold urine in.