I have a colonoscopy coming up this next friday, and it calls for 4 ducolax pills and a 255m of miralax. Thing is, is that I have taken over the counter laxatives before and I end up waking in the middle of the night and get crazy dizzy once the laxative takes effect. So, after one pill this happens, but I'm sopose to take 4??Has anyone had this happen to them? I wonder what causes the dizziness? Is there anything I can take or do to help prevent that from happening when I do the prep?