I have woke up in the middle of the night, feeling more than dizzy and having to have a bowel movement urgently. I can not make it to toilet before passing out then when I come to I can not get up until after I vomit (alot). Once I vomit and have extreme diarrhea I feel a little better and go back to sleep. I wake up feeling ok just a little weak. This has happened 3 or 4 times in the last 6 months. What can cause this?