Does anyone here know what might be good for BAD stomach bloating and distention? Also, what might be the cause?

I take meds for high blood pressure and migraine prevention. I take a fair amount of vitamins/supplements...fish oil, multi, D3, magnesium, B50, B12, etc.

Today, I picked up something from the store called Pearls and Beano.

Anyone have any ideas? Natural products? What else? I am uncomfortable. Going in for a colonoscopy in three weeks. Need some possible relief ideas asap.

Many thanks.