Low back pain is fairly prevelant and can derail your exercise training and daily activities. I have many clients with a history of several episodes of debilitating low back pain. Contrary to popular belief, most low back pain comes from repeated twisting or bending movements, usually not a single traumatic action.
Exercise is recomended to help strengthen your back, but many people don't know exactly what to do. You see them crunching, twisting, leg raising and back extending away without any clue to what they are doing to their back. They may build strength and endurance in their abdominal muscles and lower back muscles, but still have lots of back pain (or even more).
The issue at hand is that they trained the muscles at the expense of the spine. The pain, most of the time can be attributed to misallignment of the spine. It is important to establish neutral (or natural) spine position and develop stability of the spine (in all planes of motion, not just the abs or lower back). Next, learning to move through the hip joint, using the hip muscles (hamstrings, glutes, etc) will take the forces off the spine.
When there is pain, as one of my clients had this morning after moving furniture last weekend, unloading the spine and emphazing stability is paramount. This should allow you to start training again, keep neutral spine position, and progress back to where you were before.
Again, I recommend seeking treatment by a medical profession, but when you are clear, I can help you restore pain-free movement patterns and build your strength.