I have a fear of pooping in public restrooms that do not lock
Wow, is this related to your anxiety?
No I'm just very vigilant and concerned with public pooping
It is okay to be concerned about your privacy when you are going to the bathroom. You are normally very vulnerable position when using the bathroom and people could use the time to attack you.
Yeah I really need to get over it.
A non locking door seems a bit scary. If you are out and need to go in public you can try to find a Mc Donald's or something they always have locking stalls.