My child was 14 months old when I discovered her lactose-intolerance.
DD had horrible colic starting at 8 weeks old, I did try all sorts of formulas (BFing did not work out for us). I tried a soy based one, and she had horrible diarrhea instantly from that one. I used the Nutramigen formula, half that, half low iron Enfamil, I think. Then around 9 months I discovered Baby's Only Organic Formula (at that time it wasn't sold in my store, I had to order from the internet). All of a sudden her tummy was better. I had also discovered Hyland's colic tablets. I wasn't quite sure if she just outgrew it or what.
Then when she was 12 months old, I started giving her cow's milk, she would have diarrhea every afternoon. Pediatrician was not very helpful, I knew it had something to do with the dairy but he would not believe me. I kept her on the Baby's Only Organic formula for a couple more months.
Finally got a referral for milk protein allergy test, she was fine. Then I started reading on lactose-intolerance, which I figured out she was. Pediatrician said infants don't get that. She never did like cheese, other toddlers were gnawing on cheese sticks, but she never would. I know she knew it bugged her tummy.
I worried about her getting enough protein and I also wanted to stay away from soy. The powdered goat's milk was NASTY. I would make her yogurt smoothies. Yogurt is a soured dairy product, way less lactose. She would have Stonyfield yogurt, some rice milk, apricot baby food, flaxseed oil for kids in her sippy cup for the longest time.
Then I moved on to organic lactose-free milk, which she still has a cup of every day. It was still important to get protein in her since she was a picky eater, she would not eat meat for the longest time. Now she does. She did eat a lot of brown rice, etc.
She also would eat handfuls of shredded parmesan cheese. I would use it for my salads and she loved it, you would think it would be too tangy ... but hard cheese = less lactose.
We have tried dairy since she has gotten older, and usually the 2nd day or 2nd time trying something, she will get tummy cramps.
We use almond milk now that she is older for cereal.
The thing about Baby's Only Organic Formula, it was dairy based, but it's main filler was brown rice syrup, not whey. Whey is so hard for some of us to digest. I cannot handle protein drinks that have it, my stomach will have hellish cramps. I use a brown rice based protein drink for myself.
Just looked at Baby's Only website ... they have a lactose-free non-soy version now!
I was sharing my story on this chat: