Why is vesicoureteral reflux only affect children?

Outgrow or treated!: Good morning, vesicoureteral reflux (uvr) is present in 1% of all infants (primary uvr). Secondary uvr appears later due to presence of functional bladder neck obstruction. It is predominantly a problem of children as there is a spontaneous resolution of the primary uvr as children becomes adults; the bladder increases in size, ureter increases in length, and the valve control gets more efficient.