Last real gut-wrenching upchuck I had was over a year ago, when I had a particularly evil flu. I was on the crapper suffering through explosive diarrhea when, I kid you not, I erupted in vomitousness.
WTF are you gonna do when you're actively crapping and can't help but puke?
There's no escape. Since I couldn't quite reach the trash can, I had to retch all over the floor, my feet and my clothes while still exploding assward. Yay, flu!