It could be the meds that are causing problems, sometimes your kidneys don't want to digest things properly.

With your history of kidney disease and problems, I'd go to your GP and see about getting an ultrasound and urine test done.

Also, I'd strongly suggest upping your liquid intake (not caffeinated products or ones with high sugar) and possibly going to a pharmacy and getting some cranberry extract pills (or cranberry juice, with little or no added sugar).

Hope you feel better soon.