**3.4.2 Spina bifida**

Approximately 50% of children with myelomeningocele have detrusor-bladder sphincter dyssynergy, resulting in a functional bladder outlet obstruction and development of hydronephrosis (Anderson & Travers, 1993). These patients can develop the same complications as those with anatomical obstructions, including upper urinary tract dilatation, VUR, incomplete bladder emptying, recurrent urinary tract infections, and CKD (van Gool et al., 2001).
