What Causes Fainting Spell While Suffering From Stomach Upset?

My husband has fever, body aches, stomach pain, diarrhea, and passed out for about 4 minutes on the way home from work today. is it common to pass out with a stomach bug or could this have been a seizure? He has never done this before. He is a healthy 50 man and has never passed out before. He does not have any mouth our jaw pain which I would think would be common with a seizure.