My bowel movements have been getting thinner in diameter for some time now and I usually have to push hard to even get them out. What could be causing this to happen? How concerned should I be about this? I had my only colonoscopy about five years ago and the doctor told me that he found one polyp but dropped it so it could not be checked out. He told me to get another colonoscopy in one year. He also told me I had diverticulosis which I did not know I had. I would appreciate your help about this problem.