We feel your pain.... but I agree with the others here, you did the right thing. We have a cat who successfully had the major surgery for megacolon, but he was THREE when he had the surgery- not 10 or 12..... if he'd been even 7 or 8, the vet said, the odds went way down, it would be a lousy bet, a very tough recovery, and probably not a real great life for you OR him....... you did right, you helped your Montego to the Bridge instead of setting him up for a long, tough, and probably-not-too-successful recovery...... he's happy and safe and in NO discomfort now, and you had many, many years together that he wouldn't've had at all if YOU hadn't saved him from a needless death-sentence. Be thankful and happy for that- and KNOW that he was, and is.....
Sleep peacefully, Montego- you were a handsome, happy guy with a very loving family....let them know you're OK, if you can.....