what's wrong with my garter snake?

[A.Z]

My Brother & I have 4 garter snakes.
Today whilst feeding them my brother noticed some blood on the cat lit in the vivarium. When the snakes had finished eating, we cleaned them and looked very carefully.

The problem is due to one of the snakes bottoms.
It is slightly swollen, and looks a bit blocked.
We thought at first that it was just dried poo, but it's gotten worse.
We've but some antiseptic cream on it to see if that helps.
But does anyone know what's wrong?
We're at a loss here.

[infernalis]

could be a prolapse, that requires a vet to do surgery.

A close up photo would help.

[guidofatherof5]

Let us have a look at it but in the mean time keep that area moist to keep any tissue viable.

[The Snake Whisperer]

Cat litter is quite a rough substrate surface to keep garters in. I have personally found that a combination of aspen bedding at the end of the cage where I keep the swimming pool and aspen and carefresh bedding mixture at the den end of the cage, creates a good substrate situation for the snakes.
Another good bedding garters enjoy is potting soil although they can build better tunnels through the aspen and aspen/carefresh mixture.

[Stefan-A]

Cat litter is a great way to cause dehydration, too.

[Mommy2many]

I have mine in the coco fiber. They love to bury themselves underneath and then pop up their heads with dirt on their noses!

[ConcinusMan]

Cat litter? OH NO!