How Should Vomiting, Diarrhea, Throat Pain With Dysphagia And Redness Be Treated?

Hi. My daughter has been out of school since Monday because she has constintally thrown up and had diarrhea. But today she is complaining about her throat hurting when she swallows and her throat is red for what I see. Can you help us with these problems so she can get better to go to school?!? Thank you!