bowel blast Share definition Flag Noun. An expulsion of methane gas as a flatus via the anus, characterized by a loud report; a thunderous fart. I swear, dude. That bowel blast Jimmy let rip during history class blew Mr. Dickey's toupee off! bowel blast by Tummy AuGratin February 24, 2006 0 0 Get merch Get the bowel blast mug. Buy Now — $32.95 See more merch