Bedwetting or nocturnal enuresis is a condition that affects millions of children worldwide, as well as some adults and elderly individuals.

Although it is common for children younger than five years to wet the bed several times a week, this is a cause for concern in children older than five years.

For most children who wet the bed, there is no underlying disease or pathology causing the condition. Parents need to refrain from scolding, berating or frightening a child who bed wets as this will only worsen the condition, which can stem from emotional stress or major life changes such as moving house or starting a new school. Bedwetting may resolve over time as the child develops and grows up.

Bedwetting is more common among boys than girls but the cause of this gender difference is not known.

Possible triggers of bedwetting include

• Excess fluid intake before bed time
• Caffeine intake before bed time
• Excess urine production due to deficiency of vasopressin, a hormone that regulates urine production
• Urinary tract infection
• Type 1 diabetes
• Abnormality of the urinary tract
• Abnormality of the nerves that send signals from the bladder to the brain

Cause

Usually, once the bladder has become full, a signal is sent from the bladder to the brain to wake up and an individual may then get up and visit the loo. However, in young children and deep sleepers this wake up response may not occur, leading to voiding of the bladder in bed. In children, this may happen because the nerves connecting the brain to the bladder are not yet fully developed.

Symptoms

Symptoms of bedwetting include:

• Needing to visit the toilet frequently during daytime hours
• Pain on urination or fever due to possible urinary tract infection
• Constipation
• Straining to pass urine
• Excessive thirst
• Accidental passing of stools due to nerve abnormality

Diagnosis

Diagnosing bedwetting involves maintaining a diary recording the symptoms and frequency of incidents as well as the volume of urine passed each day. Any history of symptoms is also obtained and blood and urine analysis performed to check for conditions such as urinary tract infection or diabetes. In addition, an abdominal ultrasound may be recommended to check for stones in the bladder or urinary tract.

Treatment

Treatment is focused on providing support and advice to the person experiencing bedwetting and this is often enough for the problem to resolve independently in a child as they grow older. Lifestyle modifications that a child may be encouraged to adhere to include:

• Reducing fluids consumed before bedtime
• Ensuring regular toilet visits throughout the day and particularly before bedtime
• Minimising caffeine intake as caffeine is a diuretic and stimulates urine production

The adequate amount of daily fluid intake for a 4 to 8 year old child is usually 1,000 to 1,400 ml and a normal voiding frequency is 4 to 7 times per day.

Medication

Some medications that have been found to be useful in correcting bedwetting include:

• Desmopressin, the synthetic version of the hormone vasopressin that regulates urine production
• Oxybutynin which relaxes the muscles in the bladder, reducing its activity
• Imipramine which blocks certain nerve receptors in the wall of the bladder that would usually stimulate the bladder to empty