If it so happened that the poop took advantage of a weak spot in the intestines, such as a diverticuli, the poop could burst out inside the body & a massive life-threatening infection would occur. So if your anus is glued shut & you’re feverish, go to the ER.
Crazy glue is not water soluble, @AstroChuck, it’s just the skin around it gets soft & more flexible when wet, so it tends to crack off, the penis being one of the more flexible areas of the body.
So that hot bath would help if you repeatedly contracted & released your anal sphincter under warm water, a risky action though, that would encourage a burst in the intestine or a burrowing of a fistula as well.