Diaphragmatic breathing exercises will be demonstrated by a qualified physiotherapist. Exercises will be done in lying and sitting positions respectively. In supine, with the lower extremities supported over a pillow and hands positioned on the abdominal muscles, children will be asked to inhale the air through the nose, bulge the abdomen outwards as much as possible, hold their breath for a few seconds, and then exhale slowly through pursed lips. The same exercise will be then performed in both side-lying positions and in a sitting position in front of the mirror. Children will be instructed to watch the anterior abdominal wall movement during inspiration and to repeat the same action while seated on the toilet to initiate voiding. They will be asked to perform the diaphragmatic breathing exercises daily at home.

Standard urotherapy will start with the education of the children and their parents about the normal function of the bladder and external urinary sphincter and the nature of their voiding disorder. The importance of regular fluid intake (200 ml 5-6 times per day) and regular voiding will be explained. Special voiding and defecation diaries that a child has to fill out at home will be provided. An optimal voiding posture will be demonstrated in front of a mirror: a sitting position, with feet supported, hips abducted and abdominal muscles relaxed.

Same as previously described

During the treatment period, all children in both groups will be asked to keep: a 48hr daytime frequency and volume chart, and a 7-day bladder and defecation diary. Children will be re-evaluated each month after the beginning of the therapy. The analysis of the diaries and charts will start with each visit to the Clinic, noticing changes in urinary incontinence, nocturnal enuresis, defecation frequency and urinary tract infections.

Uroflowmetry with pelvic floor electromyography and post-void residual (PVR) urine measurement will be performed in both groups during monthly visits. It will be carried out twice as a child feels the need to void. PVR urine will be detected by ultrasound less than a minute after voiding.

Based on the clinical manifestations and uroflowmetry parameters, treatment result will be defined as full, partial and non-response. In children in whom urinary incontinence, nocturnal enuresis and urinary tract infections disappear entirely, treatment outcome will be described as "full response"; "partial response" when wetting episodes and urinary tract infections are reduced by more than 50%, and "non-response" when urinary incontinence, nocturnal enuresis and urinary tract infections persist. In children with constipation ≥ 3 bowel movements per week, ≤ 2 episodes of fecal incontinence per month and no abdominal pain with no laxative treatment for > 1 month will be classified as "full response".

The Dysfunctional Voiding and Incontinence Scoring System will be completed at the beginning and the end of the 12-month treatment period. This questionnaire consists of 13 questions relating to daytime and nighttime wetting, degree of wetting, frequency of urination, voiding symptoms ( straining, intermittency), pain, urgency, urge incontinence, pelvic holding maneuvers, defecation frequency, and one question concerning the impact of voiding disorder on quality of life. Parents are expected to score the frequency and intensity of wetting during the day and night in the first four questions in the presence of their child, and the last eight questions are answered in a yes or no manner. Each answer, except the last question, is scored to produce a total score of between 0 and 35. The presence of voiding dysfunction (excluding quality of life score) in both genders is indicated by a total score of 9 or more.