Mild Pelviectasis (if an isolated finding) could be due to obstruction in the urinary tract or just a benign condition. Since he had symptoms, it s better to rule out the urinary tract conditions like stone, infection, stricture, etc. You may consider discussing with your urologist about the need for further investigations along with renal function tests. CT scan or isotope Renal scan may be chosen as per the clinical profile. In some centers MR renography is also done.