I have been having chronic diarrhea for 1 1/2 weeks now. I am in the bathroom up to 20 times per day. I have started taking Imodium and when it takes effect, I'm having pencil-thin stools. I'm getting a colonoscopy tomorrow. Can Crohn's cause pencil-thin stools? From what I've read online, I've noticed that this is a cancer symptom. I am only 28 years old.