Prenatal perforation of the extraperitoneal part of the rectum, associated with a developmental defect of the pelvic floor.

Perforation of the extraperitoneal part of the rectum during foetal life is an exceptionally rare event. Two cases are reported where this has been associated with a para-rectal defect in the pelvic floor. It is postulated that in these instances, the rectal lesion is due to this abnormality. As a consequence of the perforation meconium extravasates into the buttock. This has a classic presentation which should be immediately recognised. Urgent rectal decompression, as an emergency measure before surgery, is required if further serious complications are to be prevented.