Trip to a vet did not help my snake, please help

[Bogertophis]

I've never had a vet use a Q-tip to obtain a stool sample from a snake, but that's typical for a dog if you can't or don't bring in a fresh stool sample. I can see how
that would irritate his cloaca & cause a little bleeding...shouldn't be a major problem & it was in the snake's best interest that his stool be checked, as parasites might
be part of his problem. Snakes can die from internal parasites (like protazoa, or various kinds of worms) or external parasites (like mites).

Since his cloaca is sore right now, you should change his cage substrate & use only clean paper towels to reduce debris sticking to his tail & causing infection. If the
vet didn't give you anything to put on his sore cloaca, you could get some Vetericyn (antiseptic water-based ointment designed for snake use), either online or from
a pet store...I think Petco carries it?

DO NOT feed a snake any moist dog food, or force-feed...there are many things to sort out & fix first, but if he still won't eat, I can PM you much better directions as
a last resort way to safely feed him. But that's NOT where you start...and even your vet mentioned giving the snake "hides" (for his sense of security) & leaving him
alone. Many snakes will refuse to eat (even to the point of dying) if they are handled excessively & not allowed to de-stress. Even if captive-bred, snakes are WILD
animals, not "domestic", so to be successful in keeping them, you must put their needs first. Eating is "job #1"...best to not handle any new snake until it's feeding
regularly at normal intervals on appropriate prey for at least 3 times before you handle them at all...otherwise, you interfere with their feeding instincts because a snake
that's afraid is not going to eat, & the only thing that picks up a snake in the wild is normally a predator about to EAT them. Snakes are stoic...it's not always obvious
that they are stressed when in fact, they are. But he was eating for you, for the first 3 months??? How often & what was he fed?

Another thing: trying to feed a snake too often will only stress them into refusing. When a snake refuses food, don't offer again for another WEEK. You said you were
trying 3 mice a night...? No wonder he wouldn't eat.

FYI- I'm not a fan of feeding live either, but I put the snake's needs first, & worry about switching later. He or she does need to eat.