Thank you for your query,
Your child developed crying and itching due to a urine infection or local infection like balanoprosthitis.
Do complete urine examination to look for any infection and if it is there it should be treated with antibiotics after seeing your doctor.
can be done now if it is indicated by your doctor.
It doesn't cause any sexual issues in the future.
It will be done under sedation and medication will be give to decrease the pain during and after the procedure.
It can be done from newborn period and it depends on the cultural and the clinical indication for it.
Hope I have answered your query.