Both Foreigne and Paddy are right as it goes it really depends on where your pain is being caused.

My pain was caused by my disc pushing on the nerve down my left leg so a short few sessions of traction (twice a week for 6 weeks) sorted no more pain after living with it for 18 months!

And the other treatment if for when your disc colappses onto the nerve thats what the injection does basicly reinflates the disc i know thats not exactly right but you get the idea.

You need a mri to know exactly whats wrong really but a good physio should be able to help you. I got annoyed with seeing my doctor about my back and during one really bad week i went to see a physio and see was great i crawled in and walked out! Cost me £38 which for the relief from pain was worth every penny.

Find one local and go see them asap trust me its worth it.