Yes, absolutely, and when I eat grains purposefully or inadvertently the pain comes back. I didn't even think I had all that much pain until I inadvertently ate grains and the pain came back with a vengance. All I could think of is "this is how I used to feel all the time".
Give it a try--some people get almost immediate (within a few days to a week) relief, others take a little longer.
YES! The grains cause inflammation, which leads to pain in many places, including the joints. Your joints are inflamed.
I think you should read up on turmeric, if you want relief from the inflammation, sooner than later. It will aid you in reducing the pain.
If you can eliminate the grains, you will eliminate the pains :)