Brandiwine - I used Genova's GI Effects because it's what my first LLMD recommended, and I was too sick at the time to add stool testing lab research to my list of things to research.
I was pleased with the parameters and the report, though. The LLMDs that I have seen since all recommend these tests, too, for what that's worth. I like the number of things tested for in the more comprehensive versions - candida, blood, fatty acids, parasites, potential pathogens, probiotics, inflammatory markers, etc. I remember liking that the Genova test shows you which inflammatory markers are common in various conditions (CFS, Crohn's, etc.). If you have high levels of potentially pathogenic bacteria, then it tests your strains against a variety of antibiotics (pharma AND herbal) so you will know which ones are most likely to be effective. I have read that there's no great test for parasites, as so much evidence of parasites breaks down quickly before being expelled, so I'm not sure if any test is great for that; if you suspect parasites, then it's probably best to treat for them and see if it helps, unfortunately.
I found this test very useful in practice because it steered me toward addressing high levels of pathogenic bacteria and nonexistent levels of beneficial bacteria in my gut. I had been taking probiotics and having no significant (comparatively) GI symptoms, so I would not have known that the balance was so off. I took a combination of berberine, artemisinin, olive leaf, black walnut, and wormwood, and within a month lost 25 pounds. (I gained all of that in four months on an SSRI that was for "migraines," which was what I called the three-day episodes of Lyme that I had before I knew I had Lyme, and the weight stuck around even a year after stopping the SSRI; I had no idea how much an SSRI could mess with gut bacteria.)
I was grateful to have some indication (maybe not perfect, but something) that my intestines were doing okay, and that common issues like Candida likely were not major issues for me.
I don't know anything about
other stool tests.