It really depends on the back problems. My rheumy said she can't give me lidoderm patches because they aren't FDA approved for arthritis, so it sounds like you might be beyond rheumatologist help if you are on those. But, if they aren't helping, then it might be worth seeing one, but they may just refer you somewhere else. They can at least tell you if they think it's Crohn's related. My husband has back problems and has seen an orthopaedic surgeon, a pain mgmt specialist and had physical therapy. They all refer him to someone else, but they at least had the equipment to figure out what was going on with his back.