If your in the US they will give you a ride to the hospital. We had a guy in my old call center that had seizure problems. I believe that HIPPA law is that they cannot touch you and must call an ambulance. Get your medical card ready and make sure you have enough money for the deductibles.
Really bad way to get off work IMO.
Instead get some mud from outside rub it on your butt and tell them you have had a bout with explosive diarrhea. Nobody will want come close enough to you to find out for sure.