Super sick. Again. Help? (Warning: gross)

It started with these revolting burps. They taste like stomach acid, like when you throw up bile because your stomach is empty but you need to vomit anyway. Then off to stomach cramps, which slides smoothly into watery diarrhea. I mean it's pure liquid, so substance at all. No weird color, just frequent and violent. Imodium barely touches it. At this point, both times only after diarrhea has started, do I begin vomiting. It smells like the bile/acid burps from earlier, regardless of whether there's undigested food or not. No blood. Pretty sure throughout all of this there's no fever, just whatever foul, demonic illness is coming out of my body. Has anyone here ever experienced this? It happened once before about a month and a half - two months ago. Thanks for any advice!