Welcome to HCM,
might not having any relation with problems she had.
there might be some allergy
factors playing role in this problem, might be some internal or external allergens.
Change of atmosphere as there was a Spain trip might have some role.
There are all chances to have worm infestation as there is h/o chronic diarrhea
In worm infestation there are maximum chances of having Eosinophilia.
Go for anti helminthiasis
Then go for Di-Ethyl Carbamazine (DEC ) medicine course, after consulting your doctor, which will give very good response and will give cure.
Ok and bye.