Daughter Has Had Diarrhea For The Last 3 Days, Vomited

Daughter has had diarrhea for the last 3 days, vomited once. Stool has been light in color. Today it was formed but light in color, sort of a light tan , but formed. She hasnt been eating well the last couple of days either. My husband had a day of intestinal woes right before my daughter started with it. I started her on a probiotic yesterday. Could the probiotic cause the light colored stool? Could an intestinal virus?