It is common for growing children to have recurrent urine infection. It is treated symptomatically.
You should encourage your son to drink plenty of water and pass urine regularly.
UTI is not a serious infection unless it is ascending into the kidney
and causing other problems. To rule out this, get an ultrasound
of the KUB region along with an X-ray of the KUB region. If it is normal, there is so need to worry.
He can also drink cranberry juice regularly.
Hope this helps.