Daryl's gotthe right trick, in my opinion, but I'd inprove on it by using a hide box with a hole in the top (like a closed, empty vereal box with a hole cut into one flat side). This mimics the bullsnake crawling down into a burrow. Put a few small, peach fuzzy rats into that, and leave the snake alone overnight in the dark. You can even make the box more interesting by putting a little used rodent litter into the box with the peach rats. This has worked with all of my healthy picky-feedr bullsnakes.
Of course, if it is a WC, bring it to a vet immediately. The internal parasite load may have just been high (or increased fast in captivity due to the restrived quarters and stress levels) for him to feel like eating. That would be my FIRST suggestion.
>>On releasing the animal if it doesn't eat....not sure I would do it if you keep it in captivity too long, but only 1-2 months in captivity if it was kept away from other animals is probably ok. However, this is one case I would not release it near where it was found. An animal that size will eventually end up as a dor. We saw one on 277 a few weeks ago that was a little over 7 foot, it was impossible to stradle the animal.
You know my opinion on this matter: better a DOR than a gene polluter and better NEVER released back into the wild after being in a captive collection. As sad is it is for that individual snake, it is just too little gin (for the individual) to justify the harm (to the population). I better get off this topic before I start ranting abouty all of the alterna guy tht let their sickly, unfeeding alterna go instead of keeping them in captivity and euthanizing them or working with them harder. A captive snae belongs in captive and NOT back into the wild (except as a research-orient restocking program, and such, of course.)
KJ