@TrueGoddessReincarnation not necessarily true.
Stress and anxiety can make you feel nauseated, and in certain situations phobias can cause enough stress to make you vomit . From what i've been told from a friend of mine who actually suffer from germaphobia, he not only fear germs/uncleanliness but often feel disgusted by them. To put into a germophobe's perspective, forcing themselves to touch things that they know have a lot of germs is equal to normal people forcing to touch a shit with their bare hands.
So yeah having a reaction due to extreme stress and disgust, is not that far of a reach.
Of course keep in mind that i don't know the author's intention, so it could very well be what you said.