Dysfunctional Voiding in Children

Dysfunctional voiding in children is a learned habit of contracting the external urethral sphincter or pelvic floor during voiding, causing an intermittent or staccato stream and incomplete bladder emptying, in the absence of neurological disease.

• It is commoner in girls, typically presents at ages 5 to 10 years, and is frequently linked to constipation.
• Chronic contraction against a closing sphincter raises bladder pressure, causing trabeculation, vesicoureteric reflux, hydronephrosis and renal damage if prolonged.
• Triggers include urinary infection, constipation, toilet avoidance, anxiety, and emotional stress.
• Severe form with bladder and bowel dysfunction is called Hinman syndrome.

Symptoms involve both storage and voiding.

• Intermittent, staccato or interrupted urine stream, straining to void, hesitancy and prolonged voiding.
• Urgency, frequency and daytime wetting.
• Recurrent urinary tract infections.
• Constipation and soiling.
• Holding manoeuvres.
• Palpable bladder or faecal masses; normal neurological examination.
• Differential diagnosis: neurogenic bladder, posterior urethral valves, urethral stricture, overactive bladder, bladder outlet obstruction, spinal cord anomalies (tethered cord) and anatomical anomalies.
• Complications: recurrent urinary tract infection, vesicoureteric reflux, hydronephrosis, bladder wall thickening, renal scarring, chronic kidney disease and persistent incontinence.

Uroflowmetry and post-void residual are central.

• Bladder and bowel diary and symptom score.
• Uroflowmetry with pelvic floor electromyography: staccato or interrupted curve with raised pelvic floor activity, and post-void residual by ultrasound (above 10 percent of bladder capacity is abnormal).
• Renal and bladder ultrasound: bladder wall thickening, residual urine, hydronephrosis.
• Urinalysis and culture; creatinine if renal involvement suspected.
• Voiding cystourethrogram if recurrent febrile infection (reflux) or suspicion of valves in boys.
• Urodynamics and spinal MRI if neurological signs.

Urotherapy with biofeedback is the mainstay.

• Supportive: timed voiding every 2 to 3 hours, correct toilet posture (feet supported, hips abducted, relaxed), double voiding, adequate fluids, and treatment of constipation (polyethylene glycol 0.5 to 1 g/kg daily).
• Pelvic floor biofeedback training and relaxation techniques.
• Pharmacological: alpha blocker such as doxazosin 0.5 to 1 mg at night (start low, titrate; monitor for hypotension) for persisting high residuals, and anticholinergic (oxybutynin 0.1 to 0.2 mg/kg two to three times daily) only if overactivity coexists and residual is low. Antibiotic prophylaxis (trimethoprim 2 mg/kg or nitrofurantoin 1 to 2 mg/kg at night) for recurrent infection.
• Procedures: clean intermittent catheterisation for high residual volumes unresponsive to other therapy. Botulinum toxin injection into the sphincter for refractory cases. Surgery for reflux.
• Special groups: children with renal changes need nephrology follow-up.
• Red flags: recurrent febrile infection, hydronephrosis, raised creatinine, high-grade reflux, residual above 20 percent of capacity and neurological signs.
• Follow-up: review at 4 to 6 weeks and every 3 months. Repeat uroflowmetry and ultrasound to document response. Refer to paediatric urology if no improvement in 3 to 6 months.