Lower back problem. GP, chiropractor, or specialist?
If you have intermittent back pain you could start with either. If you have other symptoms such as constant, worsening back pain, leg pain, numbness, tingling, bowel and bladder problems, weight loss, fevers, chills, night sweats, significant back injury or history of cancer, then you should start with primary care doctor, pain doctor or spine surgeon. If you do not get relief from the chiropractor then I would recommend seeing a medical doctor, preferably spine specialist.