Diseases

Studies indicate that 20% of all 5-year-old children and 10% of 7-year-olds wet the bed, and of these, up to 20% also have some degree of daytime incontinence. In addition, nocturnal enuresis is more common in boys, and diurnal incontinence is more common in girls. Secondary enuresis accounts for about one-quarter of all cases and is most often associated with some psychological stressor or anxiety.

It is important to recognize that most cases of urinary incontinence are caused by nonorganic problems, but since there are organic causes, physicians may evaluate affected children with some basic studies. Evaluation always begins with a complete history and physical exam. This differentiates between the otherwise healthy child and the child with underlying disease. The clinician will probably ask about psychological stressors, such as starting a new school, the birth of a sibling, or parental strife. In addition, in order to evaluate the severity of the symptoms, parents will be encouraged to keep a voiding diary. These are diaries which document the number of daytime voids, volumes, timing, and relationship with eating and drinking. In addition, these diaries should document the frequency of daytime wetting or nighttime wetting. Besides the history, physical, and diary, a urinalysis can be helpful to screen for organic causes, such as diabetes and urinary tract infections. For children with significant daytime symptoms, ultrasound imaging of the urinary tract including bladder and kidneys may be needed to evaluate for anatomic abnormalities. Lastly and rarely, if a neurological cause is suspected, an MRI of the spine may be indicated to evaluate for spinal cord abnormalities.

The urinary system is made up of the kidneys, ureters, bladder, and urethra. Urine is produced by the kidneys and drains via the ureters to the bladder. The bladder serves as the storage tank, stowing the urine until emptied through micturition (urinating). The act of emptying the bladder requires significant coordination between the brain, nerves, and muscles. There are two major muscles involved in urination, the detrusor and the sphincter. The detrusor is a large muscle which contracts to squeeze urine out of the bladder, and the sphincter is a group of muscles which remains contracted to keep urine in the bladder. These two muscles must work in concert, one contracting while the other relaxes, to control the flow of urine. Dysfunction in either may result in some degree of loss of urinary control. The urethra serves as the canal which carries the urine from the bladder during voiding. Achieving bladder control must be learned, and some children learn earlier than others, and therefore urinary incontinence is normal in most young infants and children, but in older children and adolescents, it is not considered normal.

It is easiest to divide childhood enuresis into two groups. Nocturnal enuresis occurs during sleep and diurnal (daytime) enuresis occurs during waking hours. Nocturnal enuresis is often referred to as bedwetting and is the most common type of urinary incontinence in children over 5 years of age. Diurnal enuresis is more often seen in younger children and more often a result of certain behaviors, though rarely it can be a sign of more serious problems. Another way to categorize incontinence is by the timing of the symptoms. If a child has good daytime bladder control but has never had a dry night, it is referred to as primary enuresis. Secondary enuresis is incontinence in an individual who has been dry for at least six months and then develops symptoms after that period.

Common causes of daytime wetting include voluntary holding of urine, urinary tract infection, constipation, and wetting with giggling. Girls are more commonly affected than boys. Less common causes include more serious issues such as neurological causes (neurogenic bladder), urinary tract anatomic abnormalities, and diabetes. Voluntary holding of urine is the most common cause of daytime wetting in young children. This is often observed in 3- to 5-year-olds who don't want to take the time to use the toilet. They are just too busy to take a break and will often fidget, squirm, and hold on to their perineal areas. Most children grow out of this on their own as they get older.

Any number of normal and abnormal things can cause nocturnal enuresis in children. Boys are more commonly affected than girls. Most young children who suffer from bedwetting are physically and emotionally normal. Although the exact cause is unknown, the bedwetting is believed to be the result of a number of nonorganic factors, including developmental issues, overproduction of urine, and an inability to respond to the normal physiological signals associated with bladder distension while asleep. Since bedwetting does run in families, experts believe there is a genetic disposition as well and if a parent experienced nocturnal enuresis as a child, there is a 45% risk that their child will also suffer from bedwetting. In addition to nonorganic causes, there are also some less common organic causes including infection, anatomic abnormalities, neurologic abnormalities, and endocrine abnormalities such as diabetes mellitus.

The prognosis of urinary incontinence is dependent upon the underlying cause, however, most children who suffer from nonorganic causes of enuresis will simply outgrow the symptoms, and less than 1% of all affected children have persistent enuresis into their adult years.

The treatment of urinary incontinence depends upon the underlying cause of the problem. The primary treatment for nocturnal enuresis most commonly involves behavioral modification. This involves positive reinforcement, encouraging frequent daytime voiding, and periodically waking the child at night, restricting fluid intake prior to bed, and alarm therapy with devices that wake the child when the underwear or bedclothes have become wet. In all cases, most children are already embarrassed by bedwetting and it is important try to reduce the social and psychological impact of the condition. Moisture alarm therapy has a high success rate and works best for motivated older children and parents. The basic process involves placing a probe in the undergarments or bed which alarms when it senses wetness. Most children will sleep through the alarm; however, most stop voiding when the alarm goes off. The child's parent must get up and help the child to the bathroom to encourage voiding, change the wet sheets and pajamas, and reset the alarm. Moisture alarms generally work within two weeks to three months and should be discontinued if the child's symptoms persist after three months. In addition to behavioral modification, there are some children who will ultimate require medication. Most commonly used medications include desmopressin acetate (DDAVP), oxybutynin chloride (Ditropan), hyoscyamine sulphate (Levsin), and imipramine (Tofranil). All of these medications have significant potential for side effects, should be reserved for a very select population, and should be used to treat the symptoms not as a cure, while awaiting natural resolution. Medications can be used intermittently for children who attend overnight camp or for sleepovers since these are 70% effective in preventing the symptoms, and bedwetting in these environments can be humiliating and stress-producing for children.

Very simply stated, urinary incontinence is defined as the loss of complete control of the act of urination or the involuntary emptying of the bladder. It is also referred to as enuresis. It can be caused by any number of factors, and in young infants and toddlers, it is usually completely normal. In order to understand the different causes better, one must have some basic understanding of the processes involved in urination

American Academy of PediatricsHealthy Children Internet Site http://www.healthychildren.org American Urological Association Foundation http://www.urologyhealth.org