We're in the process of converting a carport into a master suite, but we're stuck on plumbing. How can we get the drain out through a concrete slab? I seem to remember seeing a toilet that discharged from the back instead of the bottom, but I'm not having any luck finding anything except some rather expensive commercial fixtures. Any ideas that don't require busting up the slab? We hope to remodel again in a few years and turn the room back into a carport.