Emetophobia is an intense, irrational fear or anxiety pertaining to vomiting. This specific phobia can also include subcategories of what causes the anxiety, including a fear of vomiting in public, a fear of seeing vomit, a fear of watching the action of vomiting or fear of being nauseated...
http://en.wikipedia.org/wiki/Emetophobia#cite_note-sat-0It is considered to be one of the most common phobias in the world.