Its none of their dam business. You call in sick and just say I'm sick. Provide a Dr excuse if needed, quick trip to any urgent clinic under an hour tops.
I never understood why some people feel the need to give details when they call in sick. Just tell them your sick.
Just say food poisoning. No need to get detailed. People eat Taco Bell all the time and end up with food poisoning, and it typically isn't something so serious you'd need to see a doctor over.
Lying and having a poor work ethic are not strong Protestant Christian virtues... Maybe you should work on your values prior to visiting the Creationist "Museum" this summer.