Xelaetaks
It's debateable. Around a year ago I got a colonoscopy the doctor claimed it looked fine. Now over a year later I still have ongoing issues. There's a gastro doctor here that does endoscopies that appears to have a background in tropical medicine.
A travel doctor here recommended him I may consider consolting with him to see what he says. That said whether a regular gastro doctor could detect
parasites I'm not sure. May depend on the type too.
If they were there in abundance maybe they could see them but a lot of them seem to have a way of keeping hidden so who knows.