From what I have heard, depends on the lab. Apparently Bowen Lab specializes but I have heard they are not widely accepted. So many pathogens can mimick others in symptomology. Are you getting any adrenal response? Bloating, GI problems, stomach aches, constipation etc. Any signs of blood in the stool? Sweating? fast heartbeat, anxiety? Blood tests normal? Joint pain, muscle pain?
You might have to do what some others have had to :: in that try to narrow down the possiblities:: viral/bacterial/fungal/ parasite (nematode/cestode/protozoa) and try some different approaches one at a time.