Studies of back pain haven't been able to find an exercise program that works yet. This may be because the studies use the same exercises for everyone. It's likely that a "one- exercise-program-for-all" doesn't address the needs of each person.
A new study from Canada showed that patients got better faster when they kept all their movements in the direction that doesn't cause pain. For example if bending forward hurts then their activity and exercises were geared toward the opposite direction (extension). If bending to the left increases painful symptoms, then exercises moving to the right were taught.
This approach to back exercises is called the McKenzie Method. Some physical therapists have training in the McKenzie Method. The therapist examines the patient to find which movements cause painful symptoms. Then an exercise program is devised to help the patient move in the preferred (painfree) directions.
Ask your doctor about trying this program. He or she may know someone in your area with this type of training. You should be able to see if it will help you in a very short amount of time.