I am remodeling my bathroom off my family room that has a slab concrete with a crawl under my house the drain needs to move about 12 inches back to fit a pre fab shower kit I bought. Of course I will have to bust up the concrete to make a small run of pvc to the existing drain hole, will this be a cloging problem? Is there a flex pipe I can use to give me a small pitch I need. Thanks Robert.

Simply cut out the trap and raiser and use a PVC coupling to couple back to the drain line. You did say that this would be going straight back about 12 inches didn't you. Don't worry about the slope. The drain line has pitch. Good luck, Tom