When we got home last night, Buddha was walking with a strained step and meowing piteously, as well as attempting without much success to groom under his tail. laurie_robey and I attempted to clean him up a bit, but he was too sensitive to stand much of that.
We looked up his symptoms on the internet and they seemed to point to "unexpressed anal glands," which is to say that certain musk-bearing glands designed to mark his territory via poop were not emptying as they should. We made an appointment with Clocktower Veterinary Hospital for this morning and made him as comfortable as we could overnight.
This morning, the vet examined him and didn't find any immediate signs of infection or blockage, forced the "expression of the glands," and suggested we leave him there so they could get a urine sample to run tests to make sure that was indeed the problem.
So tonight, we'll pick him up and see what the results are. We're hoping that it's all resolved and that he will quickly recover.