Aww poor Toby bless him. It's not nice having poop stuck to your bum (not that I've had that problem lol) but you notice when your pets get a bit of poop stuck there they do act odd, as if it annoys them.

I too would suggest puting water on his bottom, even with the shower head or popping him into some water in the bottom of the bath. The water will soften the poo so it will be easier to remove and wipe away.

I have this problem sometimes with my cats, and they hate being cleaned they go mental which makes it even harder to do. They cry even more when the scissors come out, even though I have never gone near the skin with them or caught them. It's as if they know what's coming.