Thanks, Lynne. I'm trying so hard to be positive and hopeful. I just went into the kitchen to make a sliced turkey sandwich, and, just as always, right on time, Bindo leaped down from the wardrobe in a flash when he heard sounds emanating from the kitchen, and came to investigate in the hope of me giving him a little bit of it (as I always do - especially when he looks at me with those huge green eyes of his).
He ate a bit of the turkey, but then, to my surprise, walked away after a few bites, leaving some of the turkey on the counter. I guess that's because he probably still has an awful taste in his mouth from the lubricant that the vet gave him (orally) earlier today, and he couldn't really enjoy the turkey as he normally would and always does.
He's gone back up to the wardrobe - easily jumping back up there as if nothing was wrong, and nothing was/is bothering him or hurting him. It's such a mystery to me how, while definitely being constipated, he can behave so - well, almost - normally, and in such good humour. He does/has been sleeping more than usual, but other than that, and the litter box problems, looking at him and being with him, you really wouldn't know that he was feeling poorly. Even my other two cats are up there on the wardrobe with him, happily napping beside him. I'd have thought that, if he were really sick, their instinct would be to stay far away from him. Not the case at all with my boys.
Thanks for helping me to keep my spirits and my hopes up, Lynne. I really appreciate your support and your encouragement.