A bowel movement so rank, vile, and disgusting, that just the smell of it would instantly wipe out any and all life it comes in contact with, down to microscopic levels: so bad it would raise the dead from their graves, then kill them all over again. If it's possible for shit to go China Syndrome, this would be the one to do it.
Guy #1: Why was everyone running out of the restroom just now?
Guy #2: Because of me. I had a cajun sirloin and onion rings right before bed last night and it brought on a death dump this morning the likes of which God himself has never seen.