My 4 yo daughter threw up during her afternoon nap at about 2:00. She had a PB&J sandwich, some grapes, and milk to drink for lunch. Nearly 2 hours later she threw up again, mainly just clear/yellowish liquid. Not really any food. She now just threw up again after almost 2 hours, again just clear looking liquid. My concern is if this is just a stomach bug, food poisoning, or something else. The food she ate has been eaten by others in the house with no ill effects so that is at the bottom of my list.