unyquity
Many times the reason people become nauseated and throw-up after the olive oil is because: the liver has to produce enough bile to be able to process the incoming oil. If the liver is clogged or sluggish, when a large quantity of oil comes in, the liver KNOWS it can't adequately process that much oil all at once, so up it comes. It's simply the body's way of protecting itself.
HOWEVER, the flush will still be successful. That's because the very second that the liver sensed the incoming oil, it went into MAJOR production of bile...and it's the flow of bile that flushes the liver, biliary ducts and gallbladder.
A "weak digestive system" in most cases, amounts to a clogged digestive "pipeline"..which causes all kinds of digestive mayhem. I hear of people burping up oil for days, but when one's intestinal tract is flowing, healthy and unclogged, the time from when food enters your mouth to the time it is eliminated should be less than 8 hours. So ALL traces of olive oil SHOULD be gone from your stomach and upper intestines within 8 hours.
If you'd like some more information about preventing nausea during flushing, etc, here are the links to two posts I made in the past.
Flush ON!
Unyquity
//www.curezone.org/forums/m.asp?f=362&i=11413
//www.curezone.org/forums/m.asp?f=447&i=29726