Rita,
Starting with the OAT and MycoTOX is okay (not ideal), but I would also put this child on some digestive enzymes such as Zyme-Prime from Houston Enzymes (carried by New Beginnings Nutritionals). It is always possible there could be a parasite lingering too and so I agree that getting a stool test would be optimal, but if affordability is an issue right now and they are dead-set on the two other tests than go with the OAT and MycoTOX. But, honestly, a better combination would be the OAT and comprehensive digestive stool analysis. My recommendation is to never skip the OAT.
It really depends on what kind of parasite you are dealing with. Most are relatively straightforward to deal such as Giardia or Blastocystis hominis. More rare ones like Entamoeba histolytica are more challenging (but again, they are rare).
When we use botanicals we can often eradicate various gut pathogens at the same time. However, if you are dealing with Giardia for example, I would personally treat it with an antibiotic and be done with it. Giardia is a nasty parasite, but relatively easy to treat with certain antibiotics.
There is no one exact rule for this. Again, it comes down to what kind of pathogen(s) are present, along with the symptoms picture of the individual.
Many kids on the spectrum have digestive problems so I agree that if you have a child with a really bad gut than get a stool analysis done, along with an OAT. I like the MycoTOX, but it can often wait.
Sincerely,
Dr. Woeller