Suggest Treatment For Severe Fatigue And Abdominal Discomfort In A Child

Question : My 9 year old son has a history of grade IV hydronephrosis caused by UPJ obstruction (blood vessel laying over the ureter). Failed laparoscopic (sp?) surgery in September of 2014, followed by successful open surgery in March of 2015. Since then his recheck ultrasounds show continued mild hydronephrosis with caliectasis. Mag 3 renal scan shows his healthy kidney covering 70-75% with the damaged kidney covering the rest. Though he feels improved (severe vomiting, pain and nausea have completely abated), he continues to struggle with severe fatigue (it's not uncommon for him to nap every afternoon), feeling like he has to urinate very often with only minimal output, dizzy spells, paleness, and just overall stomach discomfort. He does have some parenchymal thinning to the affected kidney as well. His urologist continues to do ultrasound rechecks every six months, but also continues to insist everything is fine. He saw a nephrologist between his two surgeries, but they advised they didn't need to see him back unless the urologist indicated it was needed. My question is two fold, one, with the continued caliectasis, are we essentially waiting around to see when that kidney will completely fail? And two, should I proceed in seeking an additional opinion from a pediatric nephrologist so we could at least be working towards preserving what he has for as long as we can? Or is it indeed with range for the urologist to make that call?