hi harpreet, your son is having a large kidney
stone, which is causing pus cells in urine. Pus cells can be due to infection or just rubbing of stone against kidney wall. however, such large stones need to be treated. only uric acid stones can be dissolved with medicines (that change urine pH). smaller stones <6 mm can be pushed out by medical treatment, rest all stones need some form of surgery or lithotripsy
. I suggest u see a urologist
who will advice some Xrays or CT scan
and further treatment will be decided based on the reports. Once the stone has been treated, do get a complete stone metabolic workup of your son to decrease chances of recurrent stone. good luck.