Try RAW milk from Birchwood Dairies in Newtown, PA or they get deliveries on Wed of 1/2 gals. from another dairy at Shadybrook farms in Yardley,PA. Both places, call ahead- lookup their websites - it goes really fast.
Raw milk is whole milk, but it retains the natural enzymes needed to digest the milk, so there's less of a chance for allergies and/or bowel/stomach reactions. They don't pasturize it and homogeonize it, yet they must maintain the strictest of testing standards in order to keep their dairy functioning (the gov't would shut them down in a heartbeat I'm sure, otherwise!) Raw milk tastes like reg milk, but is better for you on SO many levels.
I'm not a doctor, so you may still want to check with one (I know that you shouldn't feed honey to infants because of a natural bacteria in it or something), but do your research 1st, because I doubt very few MD's know about this kind of thing or nutrition in general (in my experience they tend to hand out scripts instead of looking for causes and dietary alternatives for health.)
I'm assuming that you're sure it isn't a virus, or the water you're using in the formula, or changes in the formula's ingredients or something else that the baby might have sampled during the same time... (or a Vaccine or recent RX - especially antibiotics), which could have side-effects as well)!
The human body wasn't actually meant to consume dairy products once we've been weaned- that's why so many people have "lactose" intolerances (Especially with reg milk which had the natural enzymes needed by our bodies to digest it, cooked out of it when it was processed.
There are other ways to get your vitamins and minerals if you find that your baby IS allergic, and are hesitant about trying the raw milk, once you've looked into it.
You assume that the formula is ok to give your 11 month old. I question ALL prepackaged food products- constantly reading labels.
If I were to give you or anyone with small children ANYKIND of advice, it would be to start reading labels and pay attention to the foods (and meds AND Vaccines) you're giving them. Start while they're babies and introduce only healthy foods- avoiding BHT, BHA, preservatives, artificial (and so-called Natural) flavors, art. colors, MSG -in all its tricky guises such as autolyzed yeast etc.) and worst of all culprets of obesity AT ANY age- High Fructose Corn Syrup (which they put into practically everything- even most breads!) Don't wait 'til your kids will only eat processed junkfood with additives that mess-up their brain functioning. I have 3 older kids with ADHD, ODD, OCD and over the years I've come to the conclusion that what they ingest affects WHO THEY ARE as they grow not just one aspect of their health. Help them develop a taste for good foods early (it's a good time to reaccess your diet too)! Don't wait like I did and have regrets.
Good research information is the best place to start. Doctors just don't have the time and go with the only things that THEY were taught and know. We have to take back responsibility for our own health and that of our children and learn to work WITH our doctors. Libraries now have free training classes to use the internet, and have internet access there, plus you can request books from other libraries to be sent to yours, so it's easy to get info on almost anything anymore without having to pay a cent!
GET STARTED!
Good Health to you all!
P.