bladder disorders in children including bedwetting

by Diane K. Newman, RNC, MSN, CRNP, FAAN

The development of continence in a child is dependent on three variables, all maturing concomitantly:

Development of normal bladder capacity
Mature functioning of the urethra-sphincter
Development of the brain and nerve pathways that control voluntary voiding

Ten percent of all children over age four, mostly boys, experience bed-wetting (voiding while asleep), which is the most common bladder disorder seen in young people. In addition, approximately 750,000 children with such handicaps and birth defects as spina bifida or tethered cord syndrome experience ongoing bladder control problems. At least one percent of school children exhibit abnormal voiding habits and all forms of childhood wetting, other than bed-wetting, should be categorized as incontinence.

Nighttime bed-wetting (nocturnal enuresis) is common in young children. We are all born incontinent; an infant’s bladder empties involuntarily depending on stimuli and urine volume. As a toddler’s bladder, pelvic nerves and bladder control center develops, voiding gradually becomes voluntary. Bladder capacity increases one ounce (30ml) each year during the first eight years of life and girls generally have a larger capacity than boys do.

Bladder control during the day is usually achieved between the ages of two and three; nighttime control is mastered by age four, although girls are successfully toilet- trained earlier than boys. Many children achieve daytime continence while still lacking bladder control during the night. Most children outgrow bed-wetting; but around ten percent continue with nighttime bed-wetting.

Statistics show that twenty percent of four-year-olds still wet the bed, but ten to fifteen percent of these children stop bed-wetting each year and as many as one to three percent of eighteen-year-olds still wet their bed. Studies show a strong family history of bed-wetting is predictive and risk increases five to seven times for a child with one parent that experienced bed-wetting in childhood.

Children who wet the bed beyond the age of six generally need only to wait longer for their bladders to mature. Nerve pathways between the pelvis and brain may not yet be fully developed in these children or they may still have small bladders. Some children sleep so soundly that they don’t wake up even when their bladder is full and needs to be emptied. A physical or medical problem such as diabetes or a urinary tract infection can also cause the bed-wetting, so if it persists in your child past age six, you should discuss the situation with your child’s pediatrician.

Bed-wetting is usually divided into two main categories, primary (ninety percent) and secondary (five to ten percent). Children with primary bed-wetting have never experienced an extended period of dryness (two to three months) without the use of some type of treatment or medication. The usual cause of primary bed-wetting is an irritable bladder with too small a capacity. Secondary bed-wetting occurs when a child has stopped bed-wetting for an extended period of time (usually six months) and then resumes. Such factors as diabetes, urinary tract abnormalities, anatomic abnormalities, and psychological factors may cause secondary bed-wetting. In rare cases, bed-wetting can be the result of narrowing of the end of the urethra, which can be widened through stretching. Children with secondary bed-wetting often have problems associated with the complex of attention deficit disorders (ADD).

Bed-wetting causes social limitations for a child, especially about sleepovers with friends. Children commonly fear having their bed-wetting discovered by others and they sense being different from other children. In fact, children who bed-wet are more likely to report being bullied by other children. Parents often become frustrated and aggravated over the constant need to change bed linens and both children and parents may develop a sense of failure, which can be very painful for the child. As with incontinence in adults, bed-wetting in children is surrounded with myths and misinformation.

Parents must understand that children eventually outgrow the problem. Only five to ten percent of children who suffer from enuresis are found to have a physical abnormality. Only one to three percent of adolescents over age sixteen are troubled by nocturnal enuresis. Controversy surrounds the various treatment options and most professionals feel that parents should postpone medical action, at least until puberty, since most children outgrow the problem by then.

Evaluation

A pediatric urologist should evaluate children who have any signs or symptoms of bladder and sphincter dysfunction, including nocturnal enuresis that persists beyond the age of 6 years, or daytime incontinence. As part of an evaluation, the urologist will ask for a medical history about both parents and the child. Most specialists administer a questionnaire in the form of a checklist that includes any signs and symptoms related to the child’s voiding and wetting. This information and even some terms may be new to parents so a questionnaire can be helpful.

The general history includes information about bowel function, menstrual and sexual function, family-related disorders, neurologic diseases and congenital abnormalities. An extremely important part of the history is the child’s psychosocial status and family situation since bladder problems, especially bed-wetting, are early signs of child abuse.

First, the doctor does a general examination of the child including reflexes, the abdomen, genitalia and rectal area. The doctor may ask parents about the child’s voiding habits as certain awkward positions may affect bladder emptying (for example, sitting on the toilet with legs crossed activates the pelvic floor muscles, which obstructs the flow of urine from the bladder.) Often the doctor will recommend that the parents observe the child during voiding to determine possible problems with the child’s position.

Initial tests include a urine test for infection, post-void residual measurement, x-rays to determine urine flow (voiding cystourethrogram – VCUG), and an ultrasound to detect any serious problems in the bladder or kidneys. More invasive urodynamic tests may be necessary in children who have more complex problems.

Last updated February 2003

See also: Managing the Wetting , Bedwetting Alarms