15 month old lactose intolerant? had diarrhea and gave her almond milk for 2 days. poop normal then gave her whole milk again and got diarrhea.

It is possible: she has developed a lactose intolerance. Has she had diarrhea from milk before this?If she has been drinking cow's milk based formula and regular milk until now without a problem,it is also possible she has a virus, which is causing a temporary intolerance.You should discuss this with her doctor. You can also continue the almond milk or a soy based milk for 2 weeks and then try again with regular.