Very similar to normal diarrhea but fundamentally different at the same time. At first you may be minding your own business in the men's (or women's) room taking a leak like normal. While you stand there you blow of a few farts. So you proceed to try and blow off what feels like a really big powerfull fart (the most satisfying kind) and at first it is then you feel something hit the hole that shouldn't and you have to slam the door really quick. You quickly realize that you are no longer in need of a urinal (if you're a chick then you're pretty much set)so you find a stall and get ready. You know that it's liquid ass but you don't know the severity of the situation. You start to shit, as predicted it's diarrhea. Then it gets stronger and stronger. Soon you start farting between streams. The kind that reverberate in the bowl and echo in the room. Then you start farting during the streams effectively turning your ass into the most devastating form of shotgun known to man. Then the smell hits you and you think maybe you need a bucket too. This goes on for probably 15 minutes; courtesy flushing is a must. Even if you're not in public. The smell would peel the paint from the walls and burn the toilet paper that you hopefully have a costco package of standing by.
Finally it ends and you feel relieved. The cleanup is relatively easy. You may wanna dab some water on a piece of folded TP though to put out the fire. Find some mylanta and go on with your day.
Friend: "Hey what happened? I thought you just had to piss."
You: "Sorry, I got into a fight with my intestines. It ended in explosive diarrhea."
You: "Don't ask..."