There are many tests, ranging from $65 to $700. Stool tests are in vogue right now and range from $99 to $700. I like the Doctor's Data Comprehensive Stool, The Direct Labs Stool Test, The Genova G.I. Effects, and BioHealth Labs as they all yield important insights-- and there are other labs I'm sure. Generally, $350 - $390 will get you all you need. I’ve found throughout my practice that to get accurate results, you have to “hack” the tests. For example, inducing diarrhea will shake up the intestinal milieu enough to give you a good sample of everything. Another option is to extend the stool test and put two samples from two different days into a vial that is intended for one stool sample. This gives you a more accurate snapshot of what’s happening in the colon.