Lower urinary tract dysfunction and daytime wetting
How to assess a child with daytime wetting systematically, see the link between bladder and bowel, and start urotherapy correctly.
Step 1 of 12
Objectives
After this course you will be able to
- Use ICCS terms for lower urinary tract dysfunction (LUTD) correctly.
- Distinguish overactive bladder, voiding postponement, dysfunctional voiding and underactive bladder.
- Explain the link between bladder and bowel dysfunction (BBD), infection and reflux.
- Carry out an assessment with a diary, the Bristol scale, ultrasound and uroflowmetry.
- Start standard urotherapy and know when referral is needed.
Key message: in a child with daytime wetting, ask about the bowel first. The bladder problem will not resolve until constipation is treated.
Basics
Normal bladder function
- 4–5 yearsdaytime dryness in most children
- 4–7 timesnormal number of voids per day
- (age + 1) × 30 mlexpected bladder capacity
- 5–10%daytime wetting at school age
In normal voiding, the bladder stays quiet during filling, and during voiding the pelvic floor relaxes completely while the detrusor contracts. Disruption of this coordination leads to the various forms of LUTD.
Voiding 8 or more times a day is considered increased frequency, and 3 or fewer times is considered decreased frequency.
Basics
Main forms of LUTD
| Form | Typical picture |
|---|---|
| Overactive bladder | Sudden, strong urge, frequent voiding, urge incontinence, holding maneuvers. The most common form |
| Voiding postponement | The child delays voiding until the last moment because of play or embarrassment; voids infrequently during the day |
| Dysfunctional voiding | The pelvic floor does not relax during voiding; interrupted ("staccato") stream, post-void residual, frequent infections |
| Underactive bladder | Infrequent voiding, voiding with abdominal straining, interrupted stream, large post-void residual |
| Vaginal reflux | In girls, a small amount of wetting right after voiding; linked to sitting with legs together |
| Giggle incontinence | Complete emptying only when laughing, mainly in girls |
| Daytime pollakiuria | Very frequent (even several times an hour) small-volume voids during the day, no wetting; often resolves on its own |
Basics
Bladder and bowel dysfunction (BBD)
The bladder and rectum share the same nerve pathways and the pelvic floor. A full rectum presses on the bladder, increases overactivity and makes emptying harder.
- BBD is one of the most important risk factors for recurrent urinary tract infections.
- In children with vesicoureteral reflux, BBD reduces the chance of spontaneous resolution of reflux and increases breakthrough infections.
- Treating constipation alone reduces daytime wetting and infections in many children.
A parent's answer "he has a bowel movement every day" does not rule out constipation. Ask about stool form using the Bristol scale, painful defecation and soiling of underwear.
Diagnosis
History and questionnaires
- Timing and circumstances of wetting: with urgency, when laughing, after voiding, continuous?
- Number of voids, holding maneuvers, straining, character of the stream.
- Bowel: frequency, form (Bristol), pain, encopresis. Rome IV criteria for constipation.
- Urinary tract infections, reflux, previous investigations.
- Neurological and psychosocial history, ADHD.
Validated symptom questionnaires (for example, the Dysfunctional Voiding Symptom Score) are useful for measuring symptom severity and following the response to treatment.
Diagnosis
Physical examination and urinalysis
- Abdomen: fecal mass in the left lower quadrant, distended bladder.
- Genitalia: labial adhesions, meatal stenosis, skin irritation, an ectopic ureteral orifice.
- Lumbosacral region: dimple, hair tuft, hemangioma, asymmetry of the gluteal cleft.
- Neurological: lower limb reflexes, strength, gait, perianal sensation.
Urinalysis is performed in every child: infection, glucosuria, low specific gravity. If there is a history of febrile infection, a culture is also obtained.
Diagnosis
Diary, ultrasound and uroflowmetry
- 48-hour voiding diary: number of voids, volumes, fluid intake, wetting episodes. Printable form.
- Ultrasound: bladder wall thickness, post-void residual, upper urinary tract, rectal diameter (>3 cm suggests fecal loading).
- Uroflowmetry and post-void residual: the shape of the flow curve provides diagnostic information.
| Flow curve | Meaning |
|---|---|
| Bell-shaped | Normal |
| Tower-shaped (high, short) | Overactive bladder |
| Staccato (jagged) | Dysfunctional voiding, pelvic floor contraction |
| Interrupted | Underactive bladder, voiding with abdominal straining |
| Plateau (flat, prolonged) | Anatomic obstruction: urethral stricture, valve, meatal stenosis |
Post-void residual on repeated measurements is considered elevated if it exceeds 30 ml or 21% of capacity at 4–6 years, or 20 ml or 15% at 7–12 years.
Diagnosis
Who needs urodynamics?
Most children with LUTD do not need invasive urodynamics. Indications:
- Neurological signs or suspicion of neurogenic bladder.
- No response to standard and specific urotherapy.
- Upper urinary tract dilation, thick-walled bladder, high post-void residual.
- Before invasive treatment (for example, botulinum toxin).
Treatment
Standard urotherapy
It is the first step in all forms of LUTD and continues for 3–6 months:
- Explain to the child and family how the bladder works, in words they can follow.
- Timed voiding: every 2–3 hours during the day, 6–7 times a day. A watch or phone reminder helps.
- Correct posture: feet supported, knees apart, body relaxed. In girls this prevents vaginal reflux.
- Adequate fluids, mainly during the day; avoid caffeinated and carbonated drinks.
- Treatment of constipation: disimpaction first if needed, then a long-term osmotic laxative (polyethylene glycol) and regular toilet times.
- Follow-up with a diary and a motivation chart.
Urotherapy looks simple, but most failures come from the family not applying it consistently. Reviewing the diary at every visit improves adherence.
Treatment
Specific treatments
| Form | Additional treatment |
|---|---|
| Overactive bladder | Anticholinergic drug (oxybutynin, etc.) after post-void residual and constipation have been checked; in selected cases parasacral transcutaneous electrical stimulation |
| Dysfunctional voiding | Urotherapy with biofeedback to relax the pelvic floor |
| Underactive bladder | Timed and double voiding; clean intermittent catheterization for high post-void residual |
| Recurrent infection | Antibiotic prophylaxis until BBD is treated |
| Giggle incontinence | Methylphenidate in difficult cases (by a specialist) |
Anticholinergic drugs can worsen constipation and increase post-void residual. Before starting, the residual is measured and constipation is treated.
Treatment
When should the child be referred?
- Neurological signs, skin changes in the lumbosacral region.
- Febrile or recurrent urinary tract infections, reflux.
- High post-void residual, plateau-shaped flow, weak stream, straining.
- In girls, continuous wetting alongside normal voiding.
- Dilated upper urinary tract or thick-walled bladder on ultrasound.
- No response to 3–6 months of properly conducted urotherapy.
Attaching the 48-hour diary, urinalysis and, if possible, an ultrasound with post-void residual to the referral makes the first visit much more productive.
Quiz
Quiz: Lower urinary tract dysfunction
Test yourself: choose one answer.
-
A 6-year-old girl often feels a sudden urge, squats pressing her heel against the perineum, and voids 10 times a day. What is the most likely form?
Sudden urgency, frequency and holding maneuvers (Vincent's curtsy) are typical of overactive bladder.
-
What does a "staccato" (jagged) curve on uroflowmetry indicate?
A staccato curve is characteristic of failure of the pelvic floor to relax during voiding, that is, dysfunctional voiding.
-
What is the first treatment step in a child with recurrent UTIs and daytime wetting?
In BBD the first step is treatment of constipation and urotherapy. This reduces both wetting and infections.
-
In a 9-year-old child, post-void residual is 45 ml on repeated measurements. What does this mean?
At 7–12 years, a residual above 20 ml or 15% of capacity on repeated measurements is considered elevated.
-
What should be checked before starting an anticholinergic drug?
Anticholinergics can increase post-void residual and constipation, so both are assessed beforehand.
Course completed
Related articles for parents
Sources
- Austin PF, Bauer SB, Bower W, et al. The standardization of terminology of lower urinary tract function in children and adolescents: update report from the standardization committee of the International Children’s Continence Society. Neurourol Urodyn. 2016;35(4):471–481.
- Chase J, Austin P, Hoebeke P, McKenna P. The management of dysfunctional voiding in children: a report from the standardisation committee of the International Children’s Continence Society. J Urol. 2010;183(4):1296–1302.
- Farhat W, Bägli DJ, Capolicchio G, et al. The dysfunctional voiding scoring system: quantitative standardization of dysfunctional voiding symptoms in children. J Urol. 2000;164(3 Pt 2):1011–1015.
- EAU Guidelines on Paediatric Urology, 2025: Daytime lower urinary tract conditions.
This material is intended for medical professionals and is based on current clinical guidelines. Decisions about an individual patient are made by the treating doctor.