Discomfort lower back, both side, below ribs. BUN=11.8 Creatine 1.02 UltraSound of KUB=ok, 2 small renal cysts. Taking Doxycycline 100mg bid for18 day?

I am not clear. on exactly what your question is or why you are taking the doxycycline. It appears that you may have some sort of UTI or prostate infection and possibly been on antibiotics a couple of days. The Labs and Ultrasound are unremarkable. Please send us more information please.