Did this happen when you switched baby from formula to milk @ year 1?

I switched my 1 y/o daughter to whole milk 3 days ago. She was breast and formula fed, and eats dairy all the time, so i do not think it is a lactose issue. But since we switched to milk she has had really loose stool that is kind of frothy and the worst smell ever, kind of a musty woodsy smell. It is a creamy color. I know TMI but wanted to see if this is just her body getting use to milk. She has also had a pretty bad diaper rash, but that happened before we started milk, she is teething so that is what we think it is from... any ideas from any other moms and/or dads that have been through this !!