No. Your intestines are not rigid enough to withstand a vacuum strong enough to move liquid rapidly through you. Just look up any story about someone who sat on the drain valve of a pool and had their colon and parts of their large intestines sucked out their anus.

Well yeah. biologically speaking we are all just really complicated moving donuts.

That would be quite shitty straw…

Play being a giant and use a prawn as a straw.

If you want to first drink a disgusting concentrated solution of chloridic acid that would literally burn your mouth… That’s how far you can realistically get. It’s closed after that