Well corn snakes going off feed for 4-5 meals isn't much of a problem. They don't have to be sick to go off feed. Its just that they don't feel like eating and they just go off feed. Don't worry that much, maybe the next time you feed it, it'll eat.
I have snakes that goes off feed sometimes and it lasts for 3-6 months.....and they are still completely healthy, breeds for me, and lets me handle them with no problem at all. So don't worry too much for 4-5 meals...
As long as it's healthy looking, have access to fresh water, and sheds correctly, not eatting is fine.
Just make sure that the skin doesn't go too wrinkley and looks to be losing too much weight. Cause these systoms are signs of sickness...
Good Luck and Happy Herping!