I have had the near passing out thing myself, and when I told this to my doc, he said that I might very well do just that. Didn't seem that surprised nor concerned for that matter. He said that there is a nerve that runs through your belly and when the cramping is severe enough it triggers this nerve and it causes a drop in blood pressure. I forget the name for this nerve, but it has happened to me more than a few times. I feel for ya!