Hi Amy,
I think you should go and get the colonoscopy done just to ease your mind. The colonoscopy was not that bad b/c of the sedation, its the prep the day before that's not fun. Narrow stools are a sign of blockage. For me, it wasn't off and on, it was narrow for months. I just wish, like many others, i got the colonoscopy a long time ago before my cancer progressed so far. Good luck!