Urine storage and voiding are fundamental physiological processes. In clinical settings, many cases of lower urinary tract dysfunction (LUTD) are closely associated with abnormal conditioned reflexes formed in the central nervous system during the urine storage or voiding phases. Relaxation, as a core physiological and psychological state, has been shown to promote effective urine storage and facilitate smooth voiding. By repeatedly training individuals to establish a new conditioned reflex linking the sensation of urinary urgency with a state of relaxation, it may be possible to improve bladder storage capacity and voiding function. Based on this concept, the investigators have developed the world's first Micturition Desire-Relaxation Training Device (Chinese Patent No.: ZL 2020 1 0397789.4). This study aims to evaluate the clinical efficacy of this device in treating LUTD in children.

This randomized controlled trial aims to evaluate the clinical efficacy of the Micturition Desire-Relaxation Training Device in managing LUTD in children over a six-month period. A stratified block randomization method will be used, matching participants based on sex, age, and enuresis frequency. Eligible participants will be stratified by sex and age, and then randomly assigned (1:1) to either the intervention group or the sham intervention group using a computer-generated sequence. This method ensures group balance regarding baseline characteristics and enuresis severity.

In the intervention group, baseline voiding diaries will be completed prior to initiating training. The first session will be supervised by trained medical personnel, during which participants and caregivers will receive standardized instruction in device usage and bladder relaxation techniques. Each session will last approximately 10 minutes and will be conducted 3-4 times during the initial instructional phase. The device will then be provided for home use at no cost. Caregivers will receive remote support from study physicians during the intervention period. Home-based training will include 5-10 sessions per day, each lasting 10 minutes. Daily records-including images of urine output, session duration, and any adverse events-will be uploaded to a secure cloud platform for physician review. The intervention will continue for 8 weeks. Monthly records of fluid intake and voiding behavior will be maintained throughout the study. Follow-up assessments, including voiding diaries and enuresis questionnaires, will be performed at 3 and 6 months post-intervention to assess recurrence and long-term outcomes.

The sham group will follow identical baseline and training schedules; however, the device will remain inactive during each session. After 4 weeks, participants in this group will submit fluid intake and voiding records.

Primary outcome measures include the enuresis improvement rate, frequency of daytime urinary incontinence, and total number of voiding episodes within 24 hours. Secondary outcomes will include: scores for the micturition desire-awakening function, timing of enuresis events, bedtime and wake time, standardized bladder capacity, bladder variability rate, behavioral responses during incontinence, psychological/behavioral characteristics, and enuresis recurrence.

Inclusion Criteria:

1. Diagnosis according to the ICCS criteria:

   For nocturnal enuresis:

   At least one episode of involuntary nighttime urination per month for more than 3 months.

   No abnormalities in routine urinalysis. No period of bedwetting-free days lasting more than 6 months, except for organic diseases.

   For daytime urinary incontinence:

   At least one episode of intermittent urinary leakage during wakefulness per month for more than 3 months.

   No anatomical or neurological causes of urinary incontinence.

   For urinary frequency:

   The child experiences only urinary frequency and urgency, occurring during the day and before sleep, with intervals ranging from a few minutes to 1 hour. Each urination involves a small volume, less than 50% of the estimated bladder capacity [EBC (mL) = 30 + (age × 30)], typically less than 30 mL, sometimes just a few drops, while total daily urine volume remains within normal limits. When the child is engaged in play or focused, the intervals between urination are extended, and urinary frequency symptoms disappear after falling asleep.

2. Age: 5 to 18 years (inclusive), regardless of gender.

3. Voluntary participation: The child and their guardian must voluntarily participate in the trial and sign the informed consent form.

Exclusion Criteria:

1. Exclude enuresis caused by urinary tract infections, pinworms, myelitis, spinal cord injuries, epilepsy, cerebral developmental disorders, diabetes, and other neurological, urinary, or endocrine diseases, as well as transient enuresis due to excessive activity, mental fatigue, or excessive fluid intake before bedtime.
2. Exclude conditions causing urinary frequency such as neurogenic bladder, urinary tract infections, urethral syndrome, hypercalciuria, or metabolic diseases.
3. Patients who have participated in or are currently participating in other clinical trials within the past month.
4. Patients deemed unsuitable for participation in the clinical trial by the investigator.