Need help regarding milk.

Cassie • Married, Mama of 2

So when my little girl turned one we tried to give her cow milk. She had diarrhoea for a week and such a bad rash on her butt than she now has a mark...

Question will be, how can we try to give her milk again. It was full fat milk, should we try semi skimmed?

I’m fed up with baby bottles and formula and sterilising the whole thing 😒