What kind of formula is best for constipation?

I'm breastfeeding my 10 week old also feeding her formula, but enfamil lipil with iron is giving her constipation, and I've researched and it appears that similac advance and nestle good start are the best? So which one should I use? (I know I should probably consult my pediatrician about this but I was just wondering so I would know before I went in to see the pediatrician.) Thanks!

I don't know if you're keen on home remedies, but I have something simple that my grandmother has used for over 50 years.

Chamomile tea – add a bit of sugar and keep it warm and she will be pooping in no time. Most of time she will still be drinking while she fills her diaper. It also gives them a new taste.

I used it for both my kids…it also works wonders when they have upset tummies.

Good luck!