The Pope's official position:
On March 16 the Vatican released an opinion that feeding tubes are not medical therapy and cannot be withheld from a permanently unconscious person. And for those who hoped it wasn't official, Pope John Paul II confirmed the position a few days later, announcing that artificial food and water is always "morally obligatory" and removing a feeding tube is "true euthanasia by omission," violating God's law.
http://www.religiousconsultation.org...ubes_stuns.htm