Once integrity has been lost, it is impossible to regain.

In my opinion if you lose integrity it isn't impossible to get it back, Because if you try your best and be determined to get your integrity back you can, as long as you keep on trying.

Hope this helps.

the answer is anaerobic activities

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.