[Macrohaematuria in Children].

Urethritis posterior is a possible cause of asymptomatic haematuria in prepubescent boys. It is a benign lesion of the posterior urethra and its cardinal symptoms are blood spots in the underwear without any laboratory or radiologic findings. Urethrocystoscopy is the only way to confirm the diagnosis, but has been subject to criticism as it is associated with a high risk of strictures. It is advisable to adopt a "wait and see" strategy because urethritis posterior usually heals spontaneously over time. This condition is most likely caused by detrusor-sphincter dyssynergia, since behavioural intervention with biofeedback therapy offers good treatment results.