Parents just amaze me!

I don't even charge for sick days (the majority of providers in my area from my research do not so I am stuck) so you would "think" that would be more incentive to stay home with your sick child.

Colds/runny noses I can see because they can be iffy but a stomach bug? That is disgusting and unsanitary and so contagious!

I agree with the others, I would be telling these parents that you will NOT be accepting this child into your care again until they are 24 hours symptom free because you simply cannot afford to close down and inconvenience everyone else for their child.