Ugg Sue.. I thought you had a stone....You sounded like a kidney stone when you were talking about your back pain... Glad you passed it.. I know my patients with stones are so easily identified..because they are so classic in the pain they have..
As far as the sugar in your urine, hmm, my only thought is, have it rechecked, you really can't make a dx based on one abnormal test, if it comes up high again in your urine but not in your blood, I would wonder if maybe it was kidney filtering issue.....Sometimes the part of our kidney that filters out the waste and puts the other stuff back into our system, gets a little stretched and it lets things out it was supposed to put back into your system...especially since you just passed a stone..
It is only a thought though, I really don't know.... but I would for sure say to have it confirmed again.... for me, I get urinary track infections all the time so I have a urine dip test set at home... one time I dipped my urine and it showed so much sugar in my urine I almost freaked out... as it would turn out.. in my case the tester was polluted and didn't work right...