I have that problem. I was diagnosed with IBS-D when I was 16 (23 now) and it kind of fizzled out for awhile, then I started seeing mucus and bright red blood about a year ago. I totally thought I had something worse than IBS and that I had been diagnosed incorrectly all along. Two doctors and lots of tests later, it turns out it's still just IBS (colonscopies aren't bad at all - I didn't remember a thing, they knock you out pretty good). My doc said the nerves in my colon were super-sensitive, more than most ibs sufferers. She said that I could have had a bad case of gastroenteritis in the past that changed the way the nerves worked, making the colon ultra-sensitive, which of course, makes it susceptible to bleeding for various reasons, such as hard stools.Out of curiousity, has anyone else heard of this?