Bedwetting (nocturnal enuresis)

Objectives

After this topic you will be able to

• Distinguish monosymptomatic from non-monosymptomatic, and primary from secondary enuresis.
• Explain the main mechanisms of enuresis: impaired arousal, nocturnal polyuria, nocturnal overactive bladder or small nocturnal capacity.
• Assess the child with a bladder diary and avoid unnecessary tests.
• Choose between the alarm and desmopressin, and know how to use desmopressin safely.
• Recognize red flags and referral criteria.

Basics

Terminology (ICCS)

Basics

Enuresis in numbers

• 5–10%of 7-year-old children
• ~15%resolve spontaneously each year
• 1–2%of adolescents
• 2:1boys to girls

Out of every 100 seven-year-olds with enuresis, about 7 continue to wet into adulthood.

There is a strong genetic predisposition: without a family history the risk is about 15%; with one affected parent or relative about 44%; with both parents about 77%.

Enuresis has a serious impact on the child's self-esteem. Children under 5 are not treated: the family is told that wetting is involuntary, that spontaneous resolution is common and that punishment does not help. Explanation and treatment usually start at age 6–7, taking the child's and family's situation into account.

Basics

Pathophysiology

1. Impaired arousal (high arousal threshold): the signal from a full bladder does not wake the child. This is considered the key mechanism.
2. Nocturnal polyuria: the circadian rhythm of nighttime vasopressin secretion is disturbed, and nighttime urine output exceeds bladder capacity.
3. Nocturnal overactive bladder or small nocturnal capacity: at night the bladder empties at a smaller volume.

Disturbances of the circadian clock may also contribute.

These mechanisms often coexist. The diary shows which one predominates and guides the choice of treatment.

Comorbid conditions: constipation (up to 20%, 37% of it occult; treated at the same time as the enuresis), obstructive sleep apnea and snoring, obesity, attention deficit hyperactivity disorder (ADHD), allergic diseases. In ADHD, enuresis is more severe, success comes more slowly and relapse is more common.

Diagnosis

History and examination

• How many nights per week does the child wet? Primary or secondary?
• Daytime symptoms: urgency, frequency, daytime wetting, holding maneuvers (squatting, crossing the legs).
• Bowel: constipation, encopresis. Ask using the Bristol stool scale.
• Fluid intake, especially in the evening. Snoring, breathing pauses during sleep.
• Psychosocial situation, signs of ADHD, the family's attitude.

Physical examination: abdomen (fecal mass), external genitalia (meatal stenosis, labial adhesions), lumbosacral region (skin changes, dimples, hair tuft) and neurological examination of the lower limbs.

Diagnosis

Bladder diary

The diary is the cornerstone of the assessment:

• 2-day (48-hour) voiding and drinking diary: time and volume of each void, fluid intake, wetting episodes.
• One week of night measurements: wet and dry nights, each morning the diaper weight and the first morning void (nocturnal urine production).

Diagnosis

Which tests are needed?

• Needed: urinalysis (glucose, specific gravity, leukocytes), especially with sudden onset, UTI or polydipsia.
• Not routinely needed: ultrasound, blood tests, uroflowmetry, urodynamics, imaging. Functional MRI has no role.

In monosymptomatic enuresis, history, examination, diary and urinalysis are sufficient for the diagnosis. Uroflowmetry and ultrasound are done only after previous urethral or bladder surgery or when there are daytime symptoms.

Diagnosis

Red flags

Treatment

Basic advice (urotherapy)

• Inform the child and family: this is not the child's fault. Punishment is not allowed.
• Regular eating and drinking: normal fluid intake during the day, less in the hours before sleep.
• Less caffeine; limit electronic devices before bed.
• Void before bedtime and regularly through the day (5–7 times).
• If constipation is present, treat it at the same time as the enuresis.
• Waking the child at night to void is not treatment. If a wait-and-see approach is chosen, the child wears night diapers so that sleep is normal.

A wet/dry chart with "basic bladder advice" alone has not been shown to work as early treatment. Parental frustration is common; psychological support is offered when needed.

In non-monosymptomatic enuresis, daytime symptoms are treated first. This often reduces bedwetting as well.

Treatment

First line: alarm or desmopressin

Both carry a strong recommendation: the alarm for motivated families, desmopressin for proven nocturnal polyuria. Results are similar for a reduction of more than 50% in wet nights. The alarm requires patience and nighttime involvement from the family, and regular follow-up improves success. If wetting relapses after successful alarm treatment, look for overactive bladder. Choosing the option that fits the family's daily life increases the chance of success.

Treatment

Safe use of desmopressin

• Dose: oral lyophilisate (melt) 120–240 mcg or standard tablet 200–400 mcg, about 1 hour before bedtime. 120 mcg is effective and safe; structured titration up to 240 mcg if needed.
• Better response: older children, fewer wet nights, high nocturnal urine production.
• Fluids are restricted starting 1 hour before the dose and for 8 hours after it (even if the child wakes earlier), with only a few sips during that time.
• The nasal spray is no longer recommended because of the risk of overdose.

Treatment

When there is no response to treatment

1. Check adherence: is the drug taken correctly, is the alarm used every night?
2. Reassess constipation, daytime symptoms and sleep apnea.
3. Consider combining the alarm with desmopressin.
4. In a child who is desmopressin-resistant or suspected of having a nocturnal overactive bladder, add an anticholinergic to desmopressin (after post-void residual and constipation have been checked). Recent evidence shows higher success when both are started together from the beginning. Anticholinergic monotherapy is not recommended.
5. Refer to a pediatric urologist.

Multimodal treatment gives a full or partial response in about 80%. Evidence for neuromodulation and complementary therapies is of low quality. Telemedicine works for follow-up.

The psychological impact of enuresis must be taken into account. When ADHD or emotional problems are suspected, working together with a child psychiatrist or psychologist increases the success of treatment.