Urge incontinence and frequency, persisting despite oral anticholinergics and antibiotics for four months, brought a 72-year-old woman to our hospital. Plain abdominal X-ray followed by cystoscopy demonstrated a large stone (43 x 37 mm) in the bladder, and the patient underwent suprapubic cystotomy to remove the stone. The stone contained a surgical sponge, which was apparently left in situ at transvaginal hysterectomy two years previously. The sponge had most likely eroded the bladder wall and migrated into the cavity. We found a total of 17 cases reported in Japan of a surgical sponge migrating into the bladder. In particular, our case was associated with transvaginal surgery, while the other 16 cases involved transabdominal surgery.
