Lithotripsy is a noninvasive procedure used to treat kidney stones that are too large to pass through the urinary tract. Lithotripsy treats kidney stones by sending focused shock waves directly to the stone. The shock waves break a large stone into pieces small enough to pass through the urinary system. For several weeks following treatment, those small fragments are passed out of the body in the urine. Lithotripsy allows people with certain types of stones to avoid invasive procedures for stone removal.