I had similar problems and tested positive for food allergies . Taking a good probiotic repopulated my gut with the good bacteria and not the one causing the LGS.
Find a health food store, not GNC, and ask for a good one and refrigerate it. It worked in weeks but comes back in 4-6 mo if I stop.
I hope you find the same relief. Don't waaste your money on naturepath but do ask allergist.