9 Foods to avoid when your tummy hurts – #8 can kill you!

2. Dairy

Dairy products such as milk and cheese top the list of “don’t” foods when it comes to upset stomachs. For one thing, more than half the world’s population is already lactose intolerant, meaning they lack the necessary enzyme to digest dairy products.

But even if you’re not lactose intolerant, a viral or bacterial infection can affect lactase (the lactose-digesting enzyme) and could cause you to temporarily or even permanently lose your ability to digest lactose, says Dr. Chutkan.