We are all in the same boat over here. Everyone is sick, or getting over being sick. I sent home 2 DCKs on Monday. One had a fever. Clear cut, Gotta go. The other was just crying, not eating, whining, wanting snuggles all morning. I finally called mum and told her the same thing Fun&care posted "cannot keep up with our program, clearly is sick and needs to be home".
I will not hesitate to call parents to pick up if their child is not well. A fever and nausea/diarrhea is not the only reasons I would send a child home. Feeling miserable and sick is a good enough reason.