D.T.
Just like Lisa B, my daughter was also diagnosed w/ MSPI (milk & soy protein intolerance). From my daughter's pediatric GI specialist, I was given a list of foods for me and her (as she would grow & start eating table food) that listed certain foods from local grocery stores that were OK for me to eat. I learned that there was ONE type of bread that I could eat, one brand of semisweet chocolate chips that didn't have milk OR soy (YAY!!!), etc.
As Lisa said, it is a limited diet, but you can find substitutions - I used Rice milk for cooking since I couldn't use the soy milk.
I have a close friend who has just started this diet also and it was helpful for her to go to the local grocery store (Hy Vee) and they have a dietition/nutritionist on site. She walked my friend through the store and told her specifically what she COULD eat out of each aisle. She said it was a great help!
Good luck! It's hard, but possible, I did it for a year while breastfeeding. (FYI: the alternative formulas are super expensive!)
PS. My daughter, now 3 yrs, has since outgrown her intolerance and LOVES dairy products!!!