I disagree with your docotr saying he isnt "ready' for milk products. That makes absolutely NO SENSE. Like- his digestive tract isnt formed or something. You know from the fact that you breastfed him that he 'did' have a ready and functioning digestive tract.
Something has changed. Has he been on an antibiotic since he was born? They can change the flora of the gut.Were you on antibiotics or any other vitamin while breastfeeding-that could be a possibility.
In addition, I noticed a COMMON thread now is children that have adrenal fatigue- AKA low adrenal hormones. Low adrenal cortisol causes the body to stay in a heightened state of immune response- and hence food allergy, smell allergy, skin allergies, etc. Does the child have other 'off' symptoms that you have wondered about? There are specific symptoms that point to adrenal fatigue. (email me if you want to talk about them). Celiacs people are often sensitive to milk. Celiacs issues are usually always tied to adrenal disease/low hormone, look here: http://sites.google.com/site/jccglutenfree/notceliacs
Calcium can be found in many foods. Brocoli is a much better option for calcium than milk. Brocoli is a powerhouse of nutrition, is high in water after steaming, and doesn't have the excessive amounts of dead bacteria in it that pasturized milk does. Pasturized milk is said to hold quite a bit of puss, antibiotics and steriods. Milk and beef cows are fed recycled slop from food plants. Places like potato chip, candy, and cocoa processing plants give their "rejected" product to the feed lots for cheap. Feed lots love it because it puts on wieght and its cheap.
Sugar is also dehydrating. so drinking the juice isn't a better choice. However, humans instinctively have a tendancy to "self medicate" and self regulate. Your child already instinctively knew to self regulate milk because (?)it hurts his stomach.(?) Those who have low adrenal hormones (cortisol)have low blood sugar, and dosing with sugar increases glycogen to the brain, making them feel better. They will seek these things without doing it consciously. All they know is they get a sense of relief or feeling better after having it.
Another COMMON reason for vomiting in babies is a HIGH IRON INTAKE. If you are dosing with iron supplements thart could be the issue. Iron does not leave tissue, it builds up QUICKlY in babies. 30% of all pediatric death is from iron overdose, much of that , prescribed by doctors. Also think about this, baby formula and baby cereal is LOADED with high iron supplements.
Iron feeds bacteria. Bacteria must have iron to replicate. If a child had a bacterial gut infection called H. Pylori, Iron would just feed it, and I think it causes a milk sensitivity. My freind contracted H pylori and she got to where she couldnt drink milk anymore. Didi the child have an illness or stomach flu in his lifetime that could have been a point of some kind of infection of some germ?
Well there is several ideas. Bottom line, something has caused a change.