Gary's poop smells fishy sometimes. It's always been that way. He was recently tested for parasites and the vet didn't find anything. He had full blood work done and the only thing the vet saw was that the protein levels were a little high but we've just let up on the roaches a little to fix that. What else could cause fishy smelling poop?
I think you are worrying over nothing. If he received a clean bill of health he's fine. That may just be how his smells. I have two dragons and each has their own distinctive smell.