It would seem the Giantess's bowels are empty, and nothing's stopping you from being pushed all the way up into her stomach. You emerge in a pool of stomach acid, gagging, trying to rid yourself of the taste of ass.
Humiliated and squeezed into submission by a beautiful woman's turd-chute, you soon pass out, floating in her stomach. You disolve after a few hours, and as you turn into poop, the giantess sends you back out the way you came.
With a fart and a sigh, the Giantess squeezes you out, and you land with a plop in her toilet.
The End.