in my rig, once the slide is out there are 2 removable panels on the wall, one is for shower faucet, the other is for plumbing access to bathtub, and water to lines to shower.
You can sort of see the lines to the toilet, but access would be difficult to say the least.
Is your toilet a low-profile model on a raised platform? Mine is, has the original carpeting. If I had an issue, I would loosen the carpet and tie it up, cut open the side of the platform and access it from there. Once re-fastened and covered in carpet there will be nothing showing....