Dairy ladder question

Hi!

I am on 1/2 step of the dairy ladder with my 13mo. Today is day 7, and he has not shown any of his usual symptoms (we found out about his allergy when he was a month and symptoms have always been consistent)

I was getting exciting thinking he's passing, and finally outgrown the allergy, but yesterday he was screaming in pain from gas and constipation.

Should I assume these are symptoms of an existing allergy? Do I keep testing and put him in pain again? Or could these symptoms be unrelated?

I know nobody can tell me with certainty, just looking for some guidance or someone who's experienced something similar.

Thanks!