Happened upon your post and wondering how you are doing? I get narrowness like that too, and my colonoscopy was okay. Please keep us posted.
J
Hello,
Narrow stool may be a sign of narrowing or obstruction of the colon which may be due to a benign growth of colon or due to colon cancer. In addition, irritable bowel syndrome may cause irregular stools that alternate between normal and either constipation or diarrhea. Such stools may also be narrower than usual.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.