Elimination disorders

Elimination disorders manifest in childhood or adolescence as repeated voiding of urine (enuresis) or defecation (encopresis) that is inappropriate for the developmental age. Patients may have a history of other psychiatric disorders or of psychosocial stressors. The diagnosis is established based on enuresis occurring 2 times per week for at least 3 consecutive months and encopresis occurring once per month for at least 3 consecutive months. Management of enuresis consists of psychoeducation, behavioral training, and pharmacologic treatment with desmopressin or imipramine. Management of encopresis involves behavioral training and treatment of underlying constipation, if present. Both conditions have a good prognosis with high rates of spontaneous remission.

• Definition: repeated involuntary elimination of urine that is inappropriate for developmental age (e.g., bed-wetting)
• Epidemiology
  • Affects 5–10% of 7-year-olds ^[1]
  • Prevalence decreases with age.
• Types
  • Nocturnal (♂ > ♀) or diurnal (♀ > ♂)
  • Primary (patient never achieved nocturnal continence) or secondary (onset of symptoms after patient had achieved nocturnal continence)
    
• Risk factors
  • Primary enuresis: positive family history, can occur as a response to stress (e.g., recent move, sexual abuse, family conflicts) ^[2]
  • Secondary enuresis ^[1]
    • Psychosocial stress factors (e.g., problems at school)
    • Psychiatric disorders; (e.g., conduct disorder, generalized anxiety disorder) and neurodevelopmental disorders (e.g., ADHD, autism spectrum disorder)
    • Obstructive sleep apnea
    • Constipation
    • Chronic kidney disease
    • Urinary tract infection
    • Urinary tract malformation
    • Dysfunctional voiding
    • Diabetes mellitus
• Clinical features
  • General
    • Lower urinary tract symptoms
    • Nocturia
    • Constipation
  • Features that suggest an underlying disease:
    • Obstructive sleep apnea: excessive daytime sleepiness, adenotonsillar hypertrophy (see “Diagnostics” in “Obstructive sleep apnea” for more information)
    • Chronic kidney disease and diabetes mellitus: polydipsia, polyuria, weight loss, failure to thrive, hypertension (see “Diagnostics for chronic kidney disease” and “Diagnostic criteria for diabetes mellitus”)
    • Dysfunctional voiding and urinary tract malformations: daytime lower urinary tract symptoms
• Diagnostic criteria
  • Occurs at least twice per week for ≥ 3 months or causes clinical distress
  • Developmental age ≥ 5 years
• Treatment ^[1][2]
  • Treatment is typically not recommended in children under 5 years of age and if enuresis is not distressing.
  • Treatment may become indicated when enuresis causes distress or impairs social function.
  • Organic causes (e.g., urinary tract infections, urinary tract abnormalities, renal disorders) must be excluded before any treatment is started.
  • In patients with secondary enuresis, start with treatment of the primary condition (e.g., laxatives for constipation).
  • Initial approach: nonpharmacological measures
    • Fluid restriction at night
    • Psychoeducation and behavioral training
    • Timed voiding
    • Parent management training (focused on positive reinforcement of proper voiding)
  • Advanced treatment: if initial approaches are unsuccessful
    • Training with an enuresis alarm: first-line therapy in patients < 7 years of age
      • A moisture sensor embedded in the child's underwear or in a sleeping pad triggers an alarm and/or vibration, alerting the child and/or parent when involuntary urination begins.
      • Trains the child to become aware of urination and use the toilet instead
      • More likely to achieve long-term success than pharmacological options
    • Pharmacological treatment: reserved for children ≥ 7 years of age if nonpharmacological options are unsuccessful or if more rapid improvement is desired
      • Desmopressin: first-line medication, especially in patients with nocturnal polyuria
      • Tricyclic antidepressants (e.g., imipramine): second-line medication; has more side effects than desmopressin
  • Combined treatment (e.g., nonpharmacological and pharmacological options together): for children who do not respond to first and second-line therapies.

Treatment of enuresis is not indicated before 5 years of age, and the condition usually resolves spontaneously.

Enuresis alarm and desmopressin are considered the first-line treatment if behavioral measures are unsuccessful and both are effective for monosymptomatic enuresis.

• Definition: repeated involuntary or intentional elimination of feces inappropriate for developmental age (e.g., into clothes or on the floor)
• Epidemiology
  • More common in boys
  • Approx. 1% of 5-year-olds affected
• Etiology
  • Retentive encopresis: due to underlying constipation or stool impaction that then leads to overflow incontinence (approx. 80% of cases)
  • Nonretentive encopresis: no organic cause (approx 20% of cases)
  • Risk factors: psychosocial stressors (potty training, transition to solid food, starting school), positive family history
  • Associations: other psychiatric disorders, e.g., ADHD, conduct disorders, autism
• Diagnostic criteria
  • Occurs ≥ 1/month for ≥ 3 months
  • Patient's developmental age must be ≥ 4 years.
  • Symptoms not caused by a medication or another medical condition
• Treatment
  • If encopresis is due to constipation, treat the underlying constipation with fecal disimpaction, stool softeners, and dietary changes (see “Treatment” in the article “Constipation in children and adolescents.”).
  • Behavioral training with operant conditioning (e.g., rewarded scheduled toilet visits) biofeedback sessions

References:^[3]