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.