You would know without a doubt if your baby has colic. She will scream unconsolably in the late afternoon, until late at night. She will curl up her legs like her tummy hurts and cry and cry and cry no matter what you do. The Canadians have a wonderful product called "Gripe water" that they swear by for colic. I think I have seen in in Safeway. But if it is just spitting up and a little fussiness, it is probably just getting used to the new diet.
colic is a milk allergy, plain and simple. Unfortunately if you are formula feeding, than your options are soy milk, which is really bad for babies because one, it is high in estrogen, equivalent to giving them 1-2 birth control pills every day. and two, they are extremely high in manganese from being fermented in aluminum tanks, which pulls the manganese out of the aluminum, up to 500 times the daily allowance of it, which can be very harmful to a baby's brain. There are formulas that are milk free, but they are expensive. The best option if possible is to go back to breast feeding, and you to go completely off of milk products, yes everything, even butter, cheese, whey, it is hidden everywhere. But it is so worth it not to have you baby crying in pain every night. Yes they do grow out of it. Their systems just aren't mature enough to handle a protein that large yet because it is designed for an animal with 3 stomachs, not one. Both of my children had it and luckily my midwife knew what to do. I went off of milk products for about 6 months then slowly started reintroducing them, and both of my children were fine, and now both consume milk products. If you are unable to go back to breast feeding, seek out a milk free, soy free formula, your baby will be better in about a week. It takes that long for the proteins to get out their system. Good luck
T.