What Could Continual Vomiting In An Infant Indicate?

My 19 month old baby girl has been vomiting for the last 9 days. The first day she was sick five times, after that just once a day. We have been to see two doc who have checked her over and found nothing wrong no fever ear infection so on. She has been eating and drinking ok just bland food crakers dry toast and water. She seams happy durring the day a little bit under the weather but not to bad, untill about a hour before being sick when she becomes unsetled. She is very rarely ill and this seams to be draging on now.