While the causes of back pain are vast and varied, and what works for one might not for another, I think we can all agree that a strong core is a desirable thing.
I've been working my abdominal muscles regularly for a year and a half, and my incidences of back pain are about 1/10th as frequent and 1/5 as severe, and 1/20th the duration compared to before I actively started working my abdominal muscles often, and regularly.
Some of the specific exercises will be uncomfortable some days, so I switch to static leg lifting, rather than crunches, or really try every stretch in the book and retry the painful motion, which often works too.
At first working the obliques was a recipe for disaster. Had to keep from any twisting motion until they all got stronger, but now can pretty much do any variation of crunch there is pain free, most days and actually get a bit frustrated at how long it now takes for the abdominals to start burning, unless I skip doing the exercises for a week then it is depressing how quickly they start burning.
Inactivity causes me to be punished with back pain, but ever since I strengthened my core I can usually walk it off in 1/4 mile or less.
The known movements which previously could induce days of misery, I now just tighten my core muscles before doing such activities.
I really try to not take any pills, unless its really bad. Ibuprofin or Naproxen when I do. Aspirin seem better than either at headache but does nothing for back pain, for me.
Hope all who suffer back pain can find something which helps them.