Colonic mucosal ecchymoses after extracorporeal shock wave lithotripsy for upper ureteral calculus.

Bright red blood was found in stool immediately following extracorporeal shock wave lithotripsy with 2,700 shock waves to a right upper ureteral calculus beside an indwelling Double-J stent. The vital signs remained stable and bleeding did not recur. Colonoscopy revealed small areas of mucosal ecchymoses in the ascending colon. To our knowledge this effect of extracorporeal shock wave lithotripsy has not been reported previously. There is no evidence as yet that these ecchymoses are of any clinical significance for most patients.