back-door vomit Share definition Flag Diarrhea that you experience post binge drinking instead of vomit. God, I woke up this morning with the worst back-door vomit. I didn't expect that after last night. back-door vomit by BreadmanInAus November 28, 2009 0 0 Get merch Get the back-door vomit mug. Buy Now — $32.95 See more merch