I have...
Emetophobia.
Sever fear of vomit and/or vomitting.

It's terrible and I wish I didn't have it. Someone so much as looks sick I avoid them like the plague and if they ARE sick I gotta leave or I'll have a panic attack.

It's not the vomit itself or even how it looks when someone vomits, its the SOUND.
If you vomit quietly, I'm perfectly fine.
If you vomit loudly, you will not see me until you are better.