What can cause vomiting in a 19 month old child, immediately following a meal?

This has gone on for 2-days now, and we are calling the doctor in the morning, but if you can help, please do. He seems to have had a stomach virus that caused vomiting. He seems to have recovered, and is energetic and cheerful, but when he eats, he tends to eat quickly, and then immediately spit everything back up... Is there a common ailment that produces this type of vomiting?