One does not need 60k pictures to identify this as a nematode (not a crack on you btw but on the "medical system"). Nematodes share the same cylindrical shape -you can see that in the first row. You can also see the appendages in the first row. You have to understand how they diagnose a parasite infection which may explain some of the frustration. Typically, they look for the ova which is the egg and they do this since adults look similar where the ova has distinctive shapes, sizes, colors etc. Ova can only be seen under the microscope unless it is Tapeworms which the eggs can be seen with the naked eye.
So when a technician looks under the scope for ova, they have a catalog of known parasites, if they cannot identify it then you get a false negative. Keep in mind that the variety of nematodes is large (I am guessing over 1,000), the lab has probably about 15 known pathogenic nematodes. The process is nothing more than a merry go round. The best thing to do is to treat without a firm diagnosis, or that is the wisdom from a Chronic Fatigue doctor.
Fortunately, most nematodes are treated in the same way, so getting a diagnosis from lab is spinning your wheels. But if the parasites were not classified as nematodes, then the treatment protocol would differ. There are many approaches to treatment you will find, matt has some good advice on curezone. Personally I got rid of roundworm which is a nematode by using naturals (neem, boswellia, myrrh and oil of oregano (enteric coated). Enteric coated means it bypasses the stomach acids and opens in the intestine.
It might be helpful to tell where the parasites are located, for instance, anything in the stool? And references to size, although I see the finger reference. Are the all the same size?
Disclaimer: I am not a doctor so I cannot diagnose or offer treatment advice. Check with a medical professional (ugh) before starting any treatment.