just make sure he has fresh MRP fruit mix, pangea or repashy, change it after 24 hours, and he will be okay. Check for the obvious, too, like stools, then you know he's eating. what are you currently feeding him ?
Repashy (have a little Oros lid with it in) and I actually gave him 2 dusted crickets today (held them in front of his face as he wasn't interested when they were on the floor and would hop away eventually even with some legs removed!) and let him lick some Repashy off my finger so I'm a lot less worried now. I'll just do that every 3 or 4 days to make sure he's eating if I don't see any stools.