Extracorporeal shock wave lithotripsy is a procedure to break up stones inside the urinary tract, bile ducts or pancreatic duct with a series of shock waves generated by a machine called a lithotripter.

The shock waves enter the body and are targeted using an X-ray. The goal of the procedure is to break the stones into smaller pieces that can pass through the body or become easier to extract. For stones in the kidneys and ureter, fragments will exit with urine.

For stones in the bile ducts or pancreatic duct, large fragments may need to be removed by using an endoscope — a flexible tube inserted through the mouth.