Just one addendum to what I posted above for purposes of clarity of this thread. An NG tube will completely resolve a blockage caused by an ileus, because you stay hooked up to the NG tube until your bowel motility returns and feces is excreted into bag/through anus as applicable. They will not remove the NG tube until the ileus resolves. It will not necessarily resolve other blockages as Scott indicated, but will relieve “back up” which is causing intense nausea and/or vomiting by removing gastric fluids as they accumulate. And they accumulate fast.