My three year had a typical case of the flu about 10 days ago (slight fever , some vomiting , listless). He seems to be feeling much better and no longer has a fever, but the vomitting has persisted. It now occurs mostly when he gets too excited after eating or when he eats something that is not in his typical diet . He had a couple of days in which he kept food down all day, but has now vomitted twice today. Each time, the vomit is a bright pink color. He s drinking water and we re keeping him hydrated. Is there anything we should be concerned about?