Dysfunctional Voiding

Anatomy: The bladder is a muscular bag that can accept urine when it is relaxed but can contract and expel all the urine it contains. The urethra is connected to the bladder and is a hollow tube through which the urine exits once the bladder contracts. The bladder neck (a funnel-shaped junction between the bladder and urethra) and the external sphincter act as cinches and squeeze the urethra closed to help hold the urine in place. These must open (relax) prior to a bladder contraction for complete and efficient bladder emptying. Normally, the sphincter and bladder neck open first and then the bladder contracts.

Development: Infants void by reflex contraction. When the bladder is full, it sends a message to the spinal cord that then initiates a coordinated contraction: the sphincter and bladder neck open and the bladder contracts. Since adults want to control urination, the brain gains the ability to withhold a contraction, and keep the sphincter and bladder neck closed until it wishes to allow urination. It takes several years for the brain to gain this control; this develops gradually. The first phase is that the young child around two or three years old begins to feel a contraction taking place. Unfortunately for the child, by the time the contraction is felt, urination has already begun or is about to begin. "They squeeze the urethra shut." This is an intermediate transitional phase but is the first attempt to gain control. Within a few months, the child learns the feeling of fullness prior to a contraction and eventually his brain develops the ability to suppress an unwanted contraction, thus normal voiding occurs.

Dysfunctional Voiding: Some children remain in the intermediate or transitional phase. They learn to control urination by actively contracting the external sphincter during bladder contractions. Generally these children become unable to completely relax the external sphincter even when they want to urinate. In other words, this behavior becomes habitual. This causes very high bladder pressures and inefficient urination. Often the bladder is not completely emptied with each urination and becomes large over time as it holds more and more urine. These children often lose the sensation to urinate as frequently and hold their urine for long periods of time, enlarging their bladders even more, although at other times they have sudden severe urges to urinate that may result in incontinence. They become prone to bladder infections, leaking during the day and/or night, as well as other problems.

Treatment: These children are not easy to treat. Learned behaviors are difficult to overcome. Usually, these children are placed on a schedule of timed voiding - asked to urinate at specified times during the day. They are also asked to relax during urination, thus learning not to contract their sphincter muscle. They are also placed on a regimen of double voiding - asked to urinate and try again once they think they are through. Most children improve and eventually resolve their problem, but others may need biofeedback or other more complex therapy.