Had a lithotripsy 3 weeks ago, still having back spasms with lower back pain. KUB and IVP show no stones, had 3 in left kidney, I live on the heating pad, and my primary Dr. says Im a mystery. How long does this pain last after the procedure. This is disrupting my life..I think people think Im overreacting but if I lay down I and get up I have spasms in my lower back, Had none of this prior to procedure