P.S.
Hi Chritine,
I am a mom of 2 children and have taken care of MANY infants in my daycare. I would change formula. I did an extensive research on the different ingredients in the different brands when my daughter was an infant. Switch to Carnation / Best Baby. The protein is Whey, not Casein. Casein protein is found in cows milk, and is very hard on certain tummies. Also, the iron content plays a huge role in digestion in some infants. A GREAT website to get more info is www.askdrsears.com - Dr. Sears has been around forever. I bought his book 11 yrs ago when I was a new mother, and have used his advise and knowledge ever since. He has 3 sons whom are also pediatricians and one specializes in nutrition.
Take care,
P.