Well, I'm NOT a fan of "force feeding" even small prey items, but it's much gentler to do a tube-feed (liquified Gerbers chicken baby food). This is one of
many possible reasons to tube-feed...just to get some food in there so the vet can diagnose what's going on from a sample. You might want to consider
it if you don't have any luck with his appetite soon. I know how frustrating this is, believe me. I wouldn't think much of it if Corny was a BP...but corn snakes
are chow-hounds, normally. Mine are, except for my OLD guy...he's about 20, so his appetite is flaky these days & his vision is poor. But he has a good excuse.
Anyway, don't blame yourself...snakes have issues just like everything else.