I cannot be completely sure but the presence of an elavated number of protozoans was the only abnormal finding in the microscopy. I have ruled most other things out but am still open to other options.
I'm very interested in finding a good lab in EU that can distinguish individual species and possibly sensitivity.
I believe I caught it some years ago at a hospital where I was treated with amoxicilline for pneumonia. I should never have eaten their food unheated. A couple of weeks later it started big time.
The problem is that most doctors wrongly consider protozoans to be either non-pathogenic or self-limiting ie. it resolves by itself over time.