In children with the most common type of enuresis (non-organic), the exact cause is generally not known. However, most physicians believe that it is due to delayed maturation of bladder function.
In a small number of children, the cause of enuresis is organic, such as a temporary problem associated with a urinary tract infection or other illness. In these cases, the enuresis will end after the infection is successfully treated. In certain situations, enuresis can be caused by an anatomic problem of the urinary tract. If the urologist suspects this, additional tests may be ordered, including ultrasound or x-rays of the kidneys and bladder.
In many cases, a family history indicates that at least one of the parents also had enuresis as a child. If both parents had enuresis as children, there is a high probability that their children will be affected.
Most children under the age of 3 years have enuresis. However, by the age of 5 years, up to 85% of children have achieved bladder control. For this reason, enuresis is generally not diagnosed or treated in children younger than five years of age. Children between the ages of 3 and 5 years with bedwetting, if otherwise well, are usually diagnosed with delayed maturation of bladder function.
Delayed Bladder Control
Bladder control is learned gradually, only after the child is old enough to understand that such behavior is desirable and can respond to praise and rewards. Just as some children learn to walk before others, some children learn bladder control earlier than others.
Learning to ‘Hold It’
Children must overcome the pattern of voiding, or urinating, that occurs naturally in infants to achieve voluntary control of the bladder, by learning what a full bladder feels like. Since a full bladder can trigger reflex emptying, the child must learn to consciously resist the urge to void — in other words, to "hold it" longer until voiding can be done when a toilet is available. This is also referred to as “suppressing the automatic urge to void.”
The transition to consistent bladder control is not easy, and accidents are common. The conscious suppression of automatic emptying is first learned for daytime control. Eventually, the suppression signal to the bladder becomes automatic and does not require a conscious act by the child. Nighttime bladder control requires that the brain, during sleep, suppresses the automatic emptying reflex.
Every Child is Different
Since children mature at different rates, learning bladder control will also vary from child to child. Most children naturally seek parental approval and once they learn that bladder control is expected, learning to inhibit reflex contraction becomes motivation-driven.
There is no relationship between "early" or "later" onset of bladder control and learning disability in school. However, children with certain kinds of developmental disabilities are known to be more likely to have enuresis.
A "Behavior Problem"?
Enuresis is not a form of misbehavior in the sense of a child being "bad" or choosing not to comply with the wishes of the parent. A child must never be punished for having enuresis. Children are eager to please their parents, but a child with enuresis simply has not been able to achieve control. They should not be blamed or put under pressure to achieve bladder control. They just may not yet be ready.
Enuresis is not a psychological disorder, although secondary psychological problems may develop if there is tension between the child and the parent about the child's delay in learning bladder control. Harsh criticism of a child for being lazy or not being grown up will only lower self-esteem and increase emotional difficulties.