I was perfectly fine all day yesterday and all day today. I felt fine and everything was ok. Then all of a sudden about 15 minutes ago I felt like I really had to go to the bathroom so I went. i'm trying not to be too TMI about it but it was a pretty bad bout of diarrhea. And now my stomach feels all knotted up and kinda nauseous and I keep having to go to the bathroom. Is this a stomach virus or something I ate?