I had food poisoining on Thursday and Friday. I find that people rarely want to know the unsavory details. If made to come in, it will provide an excuse as to why you're throwing up.
Hey boss, I got hammered last night. I had a couple and that turned into a couple of more and you know how alcohol loosens your inhibitions. One thing turned into another and now I'm puking so much I just had to swallow to keep my ****** in place.
Or you could just tough it out at work. That builds character.
I tend to go with the bizarre. No one will believe you if you say that you are "sick." But if you call into work about an hour before hand and claim that you have been bitten by a snake and you are headed to the doctor to make sure it was not poisonous then people tend to believe you.