How do I check if my EBF 4 m.o really is CMPI?

[duende]

My DD is 4 months old, I have been dairy free since she was 2 weeks old and she was put on omperazole roughly at the same time, so we have never been sure what helped ease her reflux symptoms and general unsettled behaviour.
I'd like to check whether she is indeed reacting to diary but not sure how to do it. If i eat some dairy myself and she reacts, will it take couple if weeks for it to leave my body and mean an unhappy baby all this time??
Would I be better off giving her an oz or 2 of normal formula and watching how she behaves?

Her symptoms were always from the digestive tract, she never had rashes or eczema.

I'd like to have the option of maybe giving her a bottle of formula in the evening, at least every now and then, but don't want to force the horrible nutramigen on her if it's not necessary.

Also, if I don't need to avoid all dairy that would make my life easier.
Sorry for the massive post.! Thank you for any ideas.

My DC2 was CMPI although it took me 4 months to work it out .

Within a few days of stopping dairy in my diet, she was a new baby; the unsettled screaming behaviour was a thing of the past.

A few weeks later I was baking biscuits with DC1 and the recipe made 50 biscuits. I used soya margarine (she was fine with soya) and there was 2tbsps of milk in the whole recipe. I absentmindedly ate one whilst they were cooling and that evening she was horribly unsettled again but by the next day she was back to being her happy self. So it was a tiny 'challenge' and she quickly returned to normal. I accidentally consumed done more dairy (milk in crisps? Who knew?) a few weeks after that and the same happened again.

Thankfully for her she completely outgrew it by 14 months and is currently scoffing a 4 cheese pizza

Watching with interest.

We're in a v similar situation though ds is 6months. I've been dairy and soya free for c4months (he is ebf) and we've just started weaning. We were given nutramigen for cooking with but like OP says, it's horrid. I asked hv about reintroducing, she suggested that I eat something and see what happens. If DS has an extreme reaction then go to a&e. But I can't help but think it would be better to give a tiny bit of dairy directly to him. Any experiences?

Good luck op...I hope you find a solution x

Thank you both.
I think I will get Xmas out of the way and then have a slice of nice pizza and hope for the best...

Her reflux has flared up after the second dose of the rotavirus vaccine, need to give her a chance to recover.
She will be 5 months old early January, I'll try then.