How long is he on the septrin for?
Coccidia can cause yeasts to flare up so, I think the septrin should be used first.
Great that you have the acidophiliz on the way. Isnt it awful how much of the avipro ends up going down the drain?? Make sure you get some of it into him orally too!
OOOh I spotted you on reptileforums.co.uk - I saw you sent the fecal to pinmoore - thats the lab I use - they are super quick with getting results back to you and they are pretty accurate in their testing - the lab my vet uses doesnt identify specific parasites so I generally send my own off to confirm his results! Or, I send mine off and forget about his lab