My mother had undergone a uterus removal surgery in july but 3 months after that surgery in october urine leakage started and viscovaginal fistula was reported. For the fistula a repair surgery was done on december 12 and then she was catherized. On 23rd of december the catheter was removed but after the fistula was repaired and no leakage occurred from vagina but urine has started to leak from bladder itself drop by drop. What is its cause, is it treatable?