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.