A.  In view of your symptoms it is clear that you have urinary tract infection. It the stones are too small or they are not causing any hydronephrotic changes in the kidney they may not be see on IVP. On ultrasound alone, I will not be certain about stones of the size of 4 mm and less but would be certain about 13 mm stone in the kidney. Low backache is also supportive of atypical pain, which is not unusual in patients with kidney stones. All you need is to consult a urologist to treat your infection, re confirm the presence of stones, try and find out the cause of stones and follow general measures such as large amount of fluid intake, etc. I don't think you may need anything active to be done for the stones except for watchful waiting and periodic follow up. Invariably these stone will pass out on their own or else they will reach a narrow point in the urinary tract creating more severe pain forcing treatment.