@dulu, I just had a colonoscopy a couple of months ago, I’m 74 years old and I have had this test done every 3 to 5 years, sometimes I had polyps and other times none. I mentioned this because I also had pencil thin stools many times but thankfully no cancer, I know that it’s a symptom but not a definitive one, not sure why this happens but definitely not always due to cancer. It’s normal to worry about it but you’re getting checked out soon and that’s the best thing to do, also, the colon is very treatable and the scope can remove everything right away. I read that it can take a polyp up to ten years to become cancer so this is why routine check ups are very important, I hope that helps you feel better and good luck with the results.