Steve J. Hodges, MD
Anthony Atala, MD
BASICS
DESCRIPTION
• Incontinence: Involuntary leaking of urine due to any cause
• A “wet” child is the most common problem seen by pediatric urologists. Most wetting children will appear to no inciting cause, and some will improve spontaneously
• Enuresis: Involuntary leaking of urine while sleeping
– “Nocturnal” enuresis implies night wetting alone, “diurnal” implies day and night, although these terms are outdated according to International Childrens Continence Society (ICCS)
– Primary enuresis: Child was always wet at night
– Secondary enuresis: Child has had a dry interval for at least 6 mo before wetting again
EPIDEMIOLOGY
Prevalence
• Day or night wetting occurs in up to 25% of 4–6 yr old children (daytime incontinence is present in approximately 5–10%)
• Resolution rates of approximately 15% a year
• At 12 yr of age 4% of children are enuretic at least once a week, at 15 yr old it is 2%
• Enuresis is 3× more common in boys than girls, however daytime incontinence is more common in females in all age groups
RISK FACTORS
• Spinal dysraphism
• Urinary tract anomalies
• Developmental delay
• Family history of enuresis
• Attention deficit disorder
• Urinary tract infection
• Constipation
Genetics
• Children whose parents were not bed-wetters have a 15% incidence of bedwetting. When one or both parents were bed-wetters, the rates jump to 44% and 77%, respectively.
• Genetic research shows that bedwetting is associated with the genes on chromosomes 13q and 12q (possibly 5 and 22 also).
PATHOPHYSIOLOGY
• Daytime control attained before nighttime
• Constipation plays a major role in urinary continence
• Normal bladder control involves 3 basic components: Intact neurologic system, normal anatomy, and a mature, motivated child
• Normal urinary control occurs in stages:
– Infantile voiding (0–6 mo) low-pressure filling, reflex detrusor contractions, simultaneous relaxation of external sphincter, complete emptying, uninhibited voids
– Transitional voiding (1–2 yr) conscious sensation of bladder filling, continence achieved by controlling external sphincter, increasing bladder capacity (60 cc at birth + 30 cc/yr till 12 yr old)
– Adult voiding: Supraspinal inhibition of voiding reflex, voluntary inhibition/initiation of voiding
• Delayed voiding/defecation lead to bladder overactivity, constipation
• Bladder overactivity/constipation compounded by dyssynergy of pelvic floor, with failure to relax pelvic floor completely with emptying
ASSOCIATED CONDITIONS
See risk factors
GENERAL PREVENTION
• Aggressively prevent and treat constipation
• Ensure an environment where children are not delaying micturition or defecation
DIAGNOSIS
ALERT
Incontinence in the presence of an abnormal back exam may signal a neurologic abnormality.
HISTORY
• Child’s age—more common in young
• Child’s sex—bedwetting is more common in boys, daytime wetting more common in girls
• When did the symptoms begin? What is the pattern? Severity?
• Primary enuresis is highly associated with constipation
• Secondary nocturnal enuresis implies an acquired cause or stressor
• Dribbling upon standing or activity in girls may imply vaginal voiding
• Determine associated daytime symptoms (urgency, frequency, weak or intermittent stream, or infrequent voiding)
• History of UTI? Functional constipation?
• History of large or firm bowel movements, or encopresis, may signify constipation even in setting of normal frequency of bowel movements
• Does child show holding behavior? (curtsey or squatting in girls, holding genitals in boys)
• History of neurologic disorder?
• Family history of incontinence? UTIs? Enuresis?
PHYSICAL EXAM
• Level of physical and emotional development
• Abdominal exam—rule out masses, constipation
• Back exam—rule out signs of occult spinal dysraphism (dimples, short sacrum, spinal defect, hairy patches)
• Flattened buttocks, low gluteal cleft, or nonpalpable coccyx suggest sacral agenesis
• GU exam, rule out genital or perineal sensation disorders, signs of abuse, hypospadias, or epispadias
• Rule out urine in vaginal vault or labial adhesions in girls
• Ectopic perineal ureteral orifice can be cause of constant wetness in girls
• Rectal exam to rule out rectal stool, evaluate normal sensation and tone
• Neurologic exam
• Measure or observe urinary stream for force, caliber, straining, duration (may obtain flow/PVR)
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• Urinalysis
– Rule out UTI, microhematuria, proteinuria, glucosuria
• If any of above discovered, require thorough evaluation and treatment
• Urine culture if UA shows signs of infection
Imaging
• KUB to rule out spinal anomalies and rule out occult constipation
• Renal US to evaluate for normal GU anatomy
• VCUG only needed in the setting of febrile UTI (or any UTI in boys), hydronephrosis; allows evaluation of urethra in males
• MR urography may be needed when concerned for ectopic ureter
• Renogram rarely needed to evaluate for urinary obstruction, renal function
Diagnostic Procedures/Surgery
• Urodynamics indicated in setting of known neurologic disorder
• Cystoscopy only needed if evaluation demonstrated anatomic abnormality such as posterior urethral valves
Pathologic Findings
• Incontinence classified as structural, neurogenic, complicated, or uncomplicated
• Structural—anatomic cause of incontinence (eg, ectopic ureter in girls)
• Neurogenic—incontinence due to spinal dysraphism or other neurologic cause
• Uncomplicated—nocturnal enuresis in appropriate age group in the presence of no obvious causes on diagnostic and physical exam (least common—almost all cases have cause if look closely)
• Complicated—functional voiding disorders; significant incontinence without anatomic or neurologic cause
• Need KUB and renal/bladder US, urodynamics optional
• Other pediatric bladder disorders:
– Lazy bladder syndrome (infrequent voider)—rare voids, 2–3× a day, may have infections, associated with constipation
– Bladder overactivity—typically associated with delayed voiding and constipation, typified by uninhibited bladder contraction with no neurologic lesion
– Hinman-Allen syndrome—nonneurogenic neurogenic bladder, may be due to constipation as well
– Daytime frequency syndrome—frequent urination in a child with no other identifiable abnormalities, usually do have constipation on KUB
– Giggle Incontinence—rare form of incontinence where wetting only occurs with laughing, may be centrally mediated (brain), treated with Ritalin
DIFFERENTIAL DIAGNOSIS
• Structural incontinence:
– Ectopic ureter
– Exstrophy-epispadias complex
– Fibrotic bladder (postoperatively or postradiation)
– Imperforate anus
– Labial adhesions
– Posterior urethral valves
– Urethral duplication
– Urogenital sinus
– Vesical fistula
• Neurogenic:
– Anterior sacral meningocele, caudal tumor
– Intradural lipoma, diastematomyelia
– Myelodysplasia
– Occult dysraphism
– Sacral agenesis, spinal cord trauma, myelitis cerebral palsy
– Tight filum terminale, dermoid cyst/sinus
– Isolated nocturnal enuresis: Constipation, sleep arousal disorder, nocturnal polyuria
• Complicated incontinence:
– Giggle incontinence
– Hinman-Allen syndrome
– Lazy bladder syndrome
– Overactive bladder
TREATMENT
GENERAL MEASURES
• Behavioral measures—timed voiding, constipation therapy
• Biofeedback—physical therapy to relax external sphincter
• Diet—avoid bladder irritant, caffeine
• Perineal hygiene—voiding positioning
MEDICATION
First Line
• Treat UTI if present
• Overactive bladder
– Anticholinergic medications
Oxybutynin: Safety and efficacy of oxybutynin chloride administration have been demonstrated for pediatric patients 5 yr of age and older
Tolterodine (off label in children)
Consider β3-agonist (mirabegron off label in children)
• Constipation
– PEG 3350, enemas or suppositories, Senna laxatives, fiber supplements
SURGERY/OTHER PROCEDURES
• Structural—alleviate structural cause of incontinence
– Neurogenic—low compliance bladder may require enterocystoplasty, urethral dilation, neural stimulation, or botulinum toxin injection
– Overactive bladder—may benefit from neural stimulation, botulinum toxin injection in bladder or sphincter, rarely urethral dilation
ADDITIONAL TREATMENT
Radiation Therapy
N/A
Additional Therapies
Aggressive constipation management for severe cases may require chronic enemas or antegrade continence enema (ACE) creation
Complementary & Alternative Therapies
N/A
ONGOING CARE
PROGNOSIS
• Most patients do resolve over time as they grow, and gain more mature toileting habits
• Severe cases may lead to pelvic floor disorders (such as pelvic pain syndrome, dyspareunia) in future, so aggressive therapy indicated
FOLLOW-UP
Patient Monitoring
• Follow-up for observation of progress, adjusting medications as needed
– Structural and neurogenic causes need routine evaluations to rule out upper tract injury and monitor progress
Patient Resources
• National Kidney and Urologic Diseases
Information Clearinghouse (NKUDIC) http://kidney.niddk.nih.gov/kudiseases/pubs/uichildren/
REFERENCES
1. Feldman A, Bauer S. Diagnosis and management of dysfunctional voiding. Curr Opin Pediatr. 2006;18:139–147.
2. Humphreys MR, Reinberg YE. Contemporary and emerging drug treatments for urinary incontinence in children. Pediatr Drugs. 2005;7(3):151–162.
3. Hodges SJ. Overactive bladder in children. Curr Bladder Dysfunct Rep. 2012;7(1):27–32.
ADDITIONAL READING
Dave S, Salle JL. Surgical management of pediatric urinary incontinence. Curr Urol Rep. 2013;14(4):342–349.
See Also (Topic, Algorithm, Media)
• Dysfunctional Elimination Syndrome
• Giggle Incontinence (Enuresis Risoria)
• Hinman Syndrome
• Incontinence, Urinary, Adult Male
• Incontinence, Urinary, Adult Female
• International Children’s Continence Society (ICCS), Terminology
• Overactive Bladder (OAB)
• Sacral Agenesis
• Spinal Dysraphism
• Vincent curtsey
CODES
ICD9
• 788.30 Urinary incontinence, unspecified
• 788.36 Nocturnal enuresis
• 788.91 Functional urinary incontinence
ICD10
• F98.0 Enuresis not due to a substance or known physiol condition
• N39.44 Nocturnal enuresis
• R32 Unspecified urinary incontinence
CLINICAL/SURGICAL PEARLS
• Aggressive constipation therapy is needed.
• Enemas are most effective in treating incontinence.
• Incontinence in children is never normal and is a sign of treatable pathology.