rear outlet drainpipe

I haven't been able to find info on the installation of the drainpipe for rear outlet toilets. I'm looking at the Yorkville and Barrington both have a rough-ins of 4" on center above floor level. The drain will need to make a right angle but does it matter if goes sloping horizontally or does it need to drop vertically first. I want to add a basement bathroom near the laundry room.

Anyone ever plumbed one of these?

Thanks

Yes it can go horizontally. Just be sure to have 1/4" per ft of fall.

toilet

And it still needs a vent, especially if you are connecting to the drain from the upper level bathroom.