Hi K.,
My daughter was really gassy and constipated once I stopped nursing and switched to formula too. Here is what I found: Enfamil Gentlease worked best for her, but before I found that out I was switching from Similac to Nestle Goodstart and back to regular Enfamil again. Her DR told me that all the switching could be irratating her as well and told me to stick with one, so I started exclusively using Gentlease and after about a week I noticed an amazing difference. I now swear by it and would definitely recommend it to anyone. At this time she was 6 months old, so I also started feeding her foods that were easy to digest and good for her GI tract: organic sweet peas, pears, prunes, peaches, etc. and that helped with the constipation too. I hope this helps and welcome to Minnesota- don't let this freezing cold weather scare you, its not so bad all the time :)