Hi there!
Well, without a clinical evaluation it would be difficult to determine the cause of the pain. Possibilities that may need to be considered for backache include spinal causes such as postural issues, degenerations, inflammations; neuro-muscular causes, referred pain from other regions etc. It is not necessary for the abdominal pain to be related to the backache, though this would need to be evaluated as well. It would be best to have this evaluated by an internist initially. After a cause is identified it can be managed accordingly or specialist care may be sought. Meanwhile you could try some OTC NSAIDS and see if these seem to provide relief.
Hope this helps.
Take care!