Rally Dump

When one is full but only partway through their meal, they will "rally" by taking a massive shit. They will then come back and finish the rest of their food with the voracity of a hungry Ron Swanson.

Joe-"Yo, I can't finish this Triple Bacon Cheeseburger"
John-"Go take a rally dump"
~5-30 minutes later~
Joe-"LET'S GO!" ~Finishes food in record time~