Food Allergies Treatment

at almost 8 months old? I have twins and Madison is refusing to eat and when she does she vomits BAD. Its like pulling teeth to get her to take an ounce. This has been in the last 2 weeks. Should I try soy? My other daughter is fine with the milk? We have a dr appt in a week but any input would be great. Thanks so much!!!!!!!

My 5 mo old son has been on a hypoallergenic (very expensive) formula since age 6 weeks due to a diagnosis of lactose intolerance and milk allergy/sensitivity. Now that he is on solids he seems to tolerate milk products well and I am attempting to change to a regular formula to save money. Has anyone else tried this? Been successful? Today he is getting half and half and seems to be doing fine. I know what to look for with the lactose intolerance, but the milk allergy diagnosis was shaky so I am not sure what to look for.