Hello Dear Warm welcome to Healthcaremagic.com I have gone through your concern in depth . * Causes in child may be - inadequate hydration - genital hygiene component - calculus in the urinary tract - posterior urethral valve - pelvi ureteric junction obstructions - pyonephrosis of vivid etiology - diabetes - other systemic issues * Need extensive case evaluations with series of tests including urine culture , serum creatinine , 24 hr urine analysis , ultrasound of abdomen and pelvis , diagnostic cystoscopy , CT IVP as per the case demand & clinician concern Hope this will help you definitely . Feel free to ask any further questions in future . Thanks for patience evaluation of my answer . Regards .