Hi Bev,
You're telling my story about 3 weeks ago. Same pain, same places, right side kidney area, along with diarrhea, joint pain, and fatigue. What that was for me was flaring about to become major flaring. The pain you're talking about which is sharp and you can't walk isn't really "back pain" but it's I was told it's called "flank pain". I don't know where it comes from or if it's radiated, but when many of us with CD have major flareups, this happens.
The only thing that works for me once I reach that stage in a flare is to lay down and rest. Sometimes a couple days, sometimes only overnight. I mean laying down doing nothing but laying there with eyes open, or passing out which usually happens because the pain exhausts me. Walking or being active in any way makes the pain worse for me. It's just one of those things that only rest helps. My appetite usually shuts off, so I drink a protein drink and a lot of water to stay hydrated.
Also something to consider might be that you have a kidney stone.
I'm agreeing with Johnny, are you on medications or are you getting treated for a flare? If not, it seems like a good time to get in to your GI or at least call him. If it's Crohn's, then you're might be about to have a rough time with a flareup.
If it's kidney stones, boy they aren't any less fun either. If this is getting worse, you need to at least see your physician or get in touch with the GI immediately. Don't suffer longer than you need to.