That's an interesting idea and something I'd want to try if I can afford to at some point. It could be quite expensive though if you're going on a whim but I guess with Google translate it may be able to help find hospitals that treat parasites on the web.
I actually drove to Montreal to try out a parasite lab there but they ended up being useless. Partly due to a judgmental doctor but also that their strongyloides serology test and stool test didn't find anything.
I'd be curious if any countries offer PCR stool testing that check for multiple stuff. Also if countries mainly check for the popular parasites in their area. I guess if I ever did it I would maybe play it off as if I get sick in the country as to not seem crazy.