My buddy wants me to help him put a bathroom in his basement. I consider myself pretty handy and up to the task. But I'm a little confused on how we should do it.

He has a room that is pretty good sized already being used for storage and a laundry room. So, we know where it's going to go.

I know where I'm going to get the water supply from, that's easy. My question is on the drain for the toilet. Is it safe to just drain it into the drain that's in the floor? Or do I need to bust up the floor and add a wye into the drain from the upstairs toilet? If that's the case, then the bathroom downstairs is dead in it's tracks.

The upstairs toilet is on the other side of the house and if we put the downstairs toilet below it or even on the same wall, it will cut his basement in half.

I thought about one of those toilets, but it would have to pump the waste up the wall, across the ceiling, then wye into the waste. That's about 35-40 feet. I'd hate for a pipe to break or leak.