Greetings,
Corns produce a brown semi-solid glop containing white/yellowish crystalline urates. Sometimes you'll find a little fur in the mix. What's important is that you don't find other colors like reds or greens. If you ever have a question about your snakes health, you can scoop up some poo and take it to a herp vet. For about $10.00 +/- they'll run a fecal test and check for things like parasites.
Cheers,
Jason