Doctors Data Lab or Genova (used to be Great Smokies Diagnostic Lab)
The less you do the cheaper. "Comprehensive Stool Analysis" or just for yeast "microbiology profile."
Genova has suggested tests for CF inparticular - it is interesting just to see what is availble if you ever have a nagging suspicion.
"comprehensive digestive stool analysis"
You could give a call and see which one has the better price for what you need...Each site has sample results so you can see how your results will be presented