Rectal shyness

The feeling when you're taking a shit in a public bathroom and somebody tries to open the door and you can't remember if you locked the door or not.

I used to have rectal shyness but now I don't care who walks in on me!

Shitter shock

The feeling when you're pooping in a public bathroom and someone tries to open the door but you can't remember if you locked the door or not

I was taking a shit at Walmart and someone tried to walk in on me, gave me a real bad case of shitter shock