[Voiding disorders in childhood: from physiology to symptomatology]

Micturition is a natural event occurring several times a day, the result of a complex and partially unknown physiology. It involves different muscles (striated and smooth) as well as the central and autonomic nervous systems in an innate voiding reflex. This reflex is controlled after 2 years of age. If there is a failure or dysfunction of one of these elements, a miction disorder may appear. Two types of miction disorders are identified: neuromuscular disorders of the bladder and defective central control. Multiple factors such as constipation, bladder irritation, or an increase in abdominal pressure can interfere with the voiding reflex. The new international definitions and classifications of voiding disorders allow an easier clinical approach through careful and complete questioning and a simple clinical exam, efficient enough in most cases to provide the diagnosis and adapted treatment.