VERY active snake

[Bogertophis]

Thank you for your quick response! He last ate on the 8th of August and was offered a medium thawed rat (defrosts in the refrigerator and then warmed in water). Isn't the most frequent of eaters, typically once or twice a month.
His substrate is coconut fibers mixed with reptibark. I looked and found some urates and well as feces that was mostly fur.
Do you know of any way to check without a vet visit? The town I live in doesn't have a snake vet but I do have access to an x-ray.

An X-ray is only as good as the medical person interpreting it though. Does he have any lumps or swellings? or what we call "sausage butt"?

Keep in mind that for a 20 year old snake, he's eating quite a lot (assuming typical size for "medium" rat)...would be better off probably if you didn't feed such large meals-they're harder to digest.

I also agree, btw, to double-check the temps. in cage. Something is making him uncomfortable, sounds like.