There are many reasons for back pain.
Bed, make sure yours isn't tired and worn out, if it is, it might be time for a new one.
Weight, if you're overweight, it's going to be affecting your back and...
Posture, something we all need to work on.
Simple exercises can help, not necessarily stretches, but strengthening and balancing your entire core will help avoid back pain, injury, and will increase your functional strength in all areas.
Make sure you're incorporating back extentions, obliques work, two point box and twisting exercises in your ab routines, as well as full body exercises that link your upper and lower body. Woodchops would be a good example, and it counts as a twisting exercise too.
Taking if further, eating healthy, deadlifts and kettlebell training will make your back bullet proof.
Yes. They're over 300 years old, but gyms are finally turning to more functional training.
Beware the westernised versions with an aerobic class style that's ruining what people think kettlebell training is though.
16kg is men's starting weight, and if you can train for 10 mins on your first go without puking, you're doing it wrong.