What Causes Blood In Urine And Rise In White Blood Cells Post Surgery For Hydronephrosis?

hello there, my 7yr old daughter had surgery two years ago to treat hydronephrosis which took two years for them to detect. they preformed a vascual hitch to straighten out the ureter.the operation was a sucess but they told me she will never regain full function. everything has been fine until 12 months ago when she had pain in that kidney again along with vomiting same symptoms she was having prior to the op. pain is spontanious and always includes vomiting when pain is severe, also pain comes and goes, often not lasting more than a day or two. thi has only happened a couple of times and i was told if it happened again that we should have an ultrasound done when she is having the pain. well this happened last Wednesday. severe pain, vomiting....further tests revealed ++++ blood in urine pain came and went for 4 hours until she did a massive wee and everything went away. ultrasound was preformed after pain stopped and there didnt apear to be any change or growth in kidney since op. they tol me it could have been a stone but they arent sure. waiting list for followup with urologist is up to 12 months wait and i have home urine test strips to monitor for blood trace. however she has high levels of white blood cells now along with specific gravity....no uti present. i am worried that somthing is going on that they havent picked up.