What the ?

We know Mallory has a sensitivity to dairy products. Thus we bought some Soy formula for the trip to Fort Worth in case Mallory had a meltdown in the car. Well, we were about 40min outside Austin on the way home and she was about to lose it. I mixed up a bottle and Drew fed it to her in her car seat. All seemed well. About 3 hours later, while she was napping, she began vomiting. Poor baby! And poor Kyle, I was also napping and he had tried to deal with the situation without waking me up. But Mallory got sick on him too, so it was all over her and in her hair, the crib was a mess (thank god for ultimate crib sheets!) and so was he - he needed reinforcements and Mallory needed a bath. Poor girl got sick 5 or 6 times before she got it all out of her system. We took turns holding her while she slept for a few hours. And just to be sure she was really ok, she slept in the bassinet in our room once more. She was fine all night and woke up in the morning like nothing had happened. Clearly there's something in certain blends/brands of formula that sets her off. She vomited after her first taste of formula at 2 weeks old too. I wish I knew what it was so I could stay away from it!