How can I avoid my daughter having constipation when switching from formula to whole milk?

I've heard that drinking whole milk can cause constipation and I'd like to avoid that with my 1 year old daughter. I've also heard that putting some karo syrup in the milk will help but I don't know how much to put in; can anyone help?

give her lots of water, stay away from other dairy for a while and then gradually reintroduce it… like cheese, yogurt, etc. Just keep an eye and if you notice it being a problem, then worry. But until then just switch gradually and her system should keep up