lactose intolerant. Milk is fine for most. Gluten too. It's really not for others. The dietary science field of thought suggests that spectrum of food intolerances extends much further and the only way to tell which one your body is susceptible to is through trial and error. I mean, what happens if a lactose intolerant person continues drinking milk ignorantly? They'll have gas, bloating, and all kinds of negative consequences and wonder why. It's different than allergies.
You might find that you in a true elimination diet that her pain clears up, or gets better. Then when she gets to the part where she adds back oils, nuts or dairy or eggs that immediately she has a reaction and the pain comes back. She may be reacting to something fairly common and even healthy for others that her body just doesn't do well with.
We've been looking into this book:
https://www.amazon.com/dp/0735220107/ref=nosim?tag=cougarboard07-20