I agree that it's likely a stomach bug. You would stop ALL dairy, and give him pedialyte, popsicles, juice (watered down 1/2 & 1/2) until he's gone 24 hours without throwing up. Just make sure that he doesn't become dehydrated, don't have to worry so much about food until the vomiting has passed, then BRAT diet (bananas, rice, applesauce, toast) or crackers, goldfish, etc. A milk allergy wouldn't come on all of a sudden, but the first time you used something he was allergic to. Talk to his pedi about getting him on whole or soy milk until he's 2. Milk fat is crucial for brain development until 2 years old. Hope he feels better! BTW, is he running a temperature?
at 9:35 AM on Jan. 23, 2013