RESUMEN
Rectal perforation is a serious complication of manipulation of the anus and rectum, with catheters and thermometers. Such procedures should be performed with caution. We report a case of a 19-year-old male with retention of an intrapelvic foreign body, a mercury thermometer, which after perforating the rectum migrated into the pelvis and remained there without any symptoms for the next 7 years. A mercury thermometer, broken into 2 fragments, retained in the pelvis was noted accidentally by pelvic roentgenogram examination. An extrinsic thermometer tip over the upper rectal region was palpable by digital rectal examination. On physical examination, no infections or signs of peritonitis were observed. There were no significant abnormal findings by flexible colonoscopy. Computed tomography revealed a foreign body retained in the pelvis. Blood mercury level and a 24-hour urinary measurement of mercury were within normal limits. The patient refused any further treatment since he did not have any discomfort. The patient was in good condition and had not had surgery in the preceding 7 years.