What is the best way to check the buoyancy of your pfd?

The best way to check the buoyancy of your PFD is to try wearing it in a pool or shallow water and see how it works. To test the PFD, it must be worn correctly where straps, zippers and ties are properly fastened and any loose ends should be tucked away. Then try to relax your body and let your head tilt back. Your PFD must allow you for a comfortable swim without any restrictions. Nevertheless, the best test of all is to jump into a pool by feet first. Your PFD must stay in place and not ride up, pop off over your head or slip over your chin.

i'm pretty sure questions like these aren't allowd.   but, sure.   i can and talk : ))

when you rub, you also apply pressure, that pressure can urge the poop to come out. i think that when your rubbing, you also might be slightly breaking it up and that can further fill the stomach.