Skip to content

    Narrow stools: Should I be concerned?

    By Mayo Clinic Staff
    Jan. 11, 2024

    What causes narrow stools? Should I be concerned?

    Narrow stools that happen now and then probably are harmless. But in some cases, narrow stools — especially if pencil thin — may be a sign that the colon is narrowing or has a blockage. And that could be due to colon cancer.

    Irritable bowel syndrome (IBS) also may cause changes in the size of your stools. IBS can cause stools to be smaller, larger or narrower than usual. It also causes changes in the consistency of stools.

    Check with a healthcare professional if you notice any changes in the appearance of your stool that last longer than 1 to 2 weeks. Get medical help right away if your bowel changes happen with rectal bleeding or severe belly pain.

    1. Townsend CM Jr, et al. Colon and rectum. In: Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 21st ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed Nov. 1, 2023.
    2. Irritable bowel syndrome (IBS). Merck Manual Professional Version. https://www.merckmanuals.com/professional/gastrointestinal-disorders/irritable-bowel-syndrome-ibs/irritable-bowel-syndrome-ibs. Accessed Nov. 1, 2023.
    3. Do I have colorectal cancer? Signs, symptoms and work-up. American Cancer Society. https://www.cancer.org/cancer/latest-news/signs-and-symptoms-of-colon-cancer.html. Accessed Nov. 1, 2023.

    FAQ-20057781

    Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.

    Advertising & Sponsorship

    Mayo Clinic Press

    Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.

    Fuel groundbreaking medical research!

    Give Today

    Your donation powers the future of medicine and helps save lives.

    Give Today