Ah please don't do this to yourself Lyndsay. You the same age as my daughter and it makes me feel bad that you are making yourself so miserable at this great age of your life. You'd have a lot more symptoms that just that (which really isn't a symptom anyway! I saw your other post, the poop looks great! Especially the color) Throughout your life your bowels will change, sometimes for a week, sometimes for YEARS. I had hard stools for years, then they got soft for years and years, then about 5 years ago they got hard again. Then once in a while there'll be one about as thin as a cigar. It happens. When they are REAL soft they will be thinner, flatter, it's only natural. I had a flex sig awake and it was nothing - so don't be afraid to be awake, you can even watch it on the screen as he explains things.
You don't want to get unnecessary ct tests with radiation and all that. Just get the flex sig if this is what your doctor deemed a good test for your "symptoms".