Kidney stones are far less common in children than in adults but they occur for the same reasons. Minerals form crystal deposits in the kidneys which grow into stones, most of which are about the size of a grain of sand. Most remain in the kidney but up to a third may migrate from the kidney to lodge in the ureters, the tubes that lead from the kidney to the bladder. Stones that remain in the kidney, although often painless, can be the source of recurrent urinary tract infections. Those that lodge in the ureter can create a severe colicky pain.
Another symptom is blood in the urine (hematuria). Most of these stones can be treated with extra-corporeal shock wave lithotripsy (SWL), a completely non-invasive procedure. The child is placed under anesthesia and sound waves of specific frequencies are focused on the stones to shatter them into fragments small enough to be easily passed during urination. In instances in which the stones are too large to be treated with SWL or fail to respond to SWL, Cleveland Clinic has developed a number of minimally invasive procedures that allow the stones to be removed. These operations are so efficient and so minimally traumatic that it is not unusual for the child to return home on the same day the procedure is conducted.