How do you know if your child has an allergy to cow's milk?

My son who just turned15 months, I think has an allergy to cow's milk.
I started giving him whole milk about two weeks ago, and about 5 days after taking it he has had diarreah ever since.
But he is still drinking, and doesn;t have a fever.
I was just wondering if anyone else is going through this.
I have heard some information on a cow's allergy, and it says sometimes the child may outgrow it.

here is a website with tons of info.

milk allergies are very common and yes most kids grow out of them.

if he is allergic there are many alternatives, rice milk, soy milk, goats milk etc Source(s): http://www.drpaul.com/illnesses/milkalle...

I don't have experience with this, but this website is great for all food allergies!!
http://www.foodallergysolutions.com/food...
Take him off the milk and try soy milk. If the diarreah goes away that should be a good sign that it was the cow's milk. My daughter is also on soy milk and she is a very healthy 15 month old! I just make sure to put a drop of vitamins in her cup. Also does you child drink juice? My daughter can't have juice anymore... the sugar gives her diarreah. Call your child's doctor she may reccomend some good diet changes. Good luck.
It could be, or it could be that he just got a not so good batch of milk. The only way to be sure is to try it again and see, if then, maybe you should switch him to lactaid milk. But make sure you speak to the doctor first because your little one is still quite young.
4 year old and 1 one the way!
go to your doctor and get an allergy test .. he may have an allergy to something else that he ate because usually you get hives or throat swelling when you are allergic to food .. but im not a doctor so it is best to go see a professional