Is there such a thing as a 24 hour flu or bug?

Yes, there is such thing as a 24 hour flu. Just be sure, to wait a good 24 hours of feeling better before returning to your daily routine. Your body needs to take time to heal and get better. You don't need to add any extra stresses, if they are at all preventable. Also, try to eat light foods because flu symptoms can hide for periods of time and reappear later, and let's just say you don't want those Chili Chesse Fries in your stomach on your way to the bathroom. ;)