When I lost the Terminator the vet. thought that he may have had IBD but he wasn't aware of a case in Colubrids; as it turned out the Terminator was terminated by some other funky virus - but some of the symptoms were the same, i.e. convulsions, upchucking, flopping over, etc. but he was active, could still constrict and didn't lose too much weight; and he only really lost his ability to right himself the last day.
Like the others say, if he's acting fine otherwise he should be OK - but if he starts to go down with something with symptoms like IBD I'd euthanisize the snake unless the vet can treat it; I watched my prize snake go down over the course of a month from some wierd virus and it was awful - if I ever come across a situation like that again I'll put a snake down even if he could live another month or so because it's just prolongs the suffering of an animal that's going to die anyway.
Hope things work out for your snake and he appears healthy in the pic. After you keep kings for a while it doesn't take much to notice the smallest changes in their behavior.
-John