I am wanting to put a bathroom in my basement. There is a stack from the kitchen in on corner that goes straight into the ground and then goes across the room underground diagonally. I know this by the location of the floor drain and the stack on the other side of the basement. My question is what size pipe is needed to add on a toilet? It apears to be a 3″ pipe before it goes underground. Would that be big enough for a toilet? Will the floor drain being after the toilet cause probs? Can i connect the pipes above floor level? Any help is appericiated!