After straining my back a few years back while painting the garage floor, My doctor recommended either Pilates or Yoga. Having tried both, I prefer Pilates but both seemed to be effective. After searching the racks at Barnes and Nobles, I found
this book that seemed to fit my needs best. I've been doing 30 minutes a day, 5 days a week for a few years now and have had no more back problems. I've got about 5 that I used before and after excercising which take about 5 minutes to do. A side benefit is that where in the past I had a hard time bending at the waste and touching the floor with my fingertips, now I can almost lay my palms on the floor without bending my knees -- so my flexibility had increased significantly.
My wife is a proponent of Chiropractic therapy, but she keeps going back every few weeks to a month for another "crack". Once I started doing the pilates, my backproblems have gone away.
I agree though, anything like this should start with your doctor to ensure that you understand what the problem is, and that your treatment won't make it worse.
A couple of other observations...
1) My doctor said that nowadays they discourage the "Take some pain relievers and lay on the couch for a week" approach since if the back problem is muscular, the muscles need to be flexed and blood flow increased. Neither of these happen on the couch.
2) "Stretch away from the pain". If it hurts when you bend forward, then start by stretching back. Or vice versa until you regain enough flexibility to stretch in all directions.
First: SEE YOUR DOCTOR!