Do you know or have an idea of what the problem might be?
Any MRI or Xrays yet?
Gp could order those I think, then you'll know better if a specialist is needed or just some good therapy.. Gp could order a PT assessment/evaluation that might be valuable also..

I would do some web searches & ask friends/family if they know of good PT, DC, Osteo etc.. esp if it might be soft tissue related and not any major or surgical scenario.
Find some experts in your city and see what they say..

Or if you can describe what your back issues are we might be able to point you in a direction..
We have a spinal forum also..
http://neurotalk.psychcentral.com/forum22.html