Medex Lab tests

[Pickwick]

Does anyone have any experience with Medex lab tests? I want to get a whole range of general tests now I've reached 50, including some at hospital next time I am in Bangkok (which unfortunately won't be any time soon for various reasons). In the meantime I wanted to get some of the basic blood tests with additions, specifically FIT blood test, with a view to arranging a colonoscopy within the next six months to a year.

 

I am, however, in the middle of nowhere and I am unsure how to find a reliable or certified lab for such tests. Phitsanulok is the closest bigger town I suppose, though it is not so difficult to get to Nakhon Sawan either. Looking for hospitals in these areas that offer the FIT (and struggling as my medical Thai is not yet up to scratch) I stumbled upon Medex, based in Bangkok but with labs in many provinces, including Nakhon Sawan. I am not sure how I check their (or any other labs) credibility.

 

If anyone has any experience or advice I'd be very grateful.

Edited July 9 by Pickwick
typo