What causes narrow stools? Should I be concerned?
Answer From Elizabeth Rajan, M.D.
Narrow stools that occur infrequently probably are harmless. In some cases, however , narrow stools — especially if pencil thin — may be a sign of narrowing or obstruction of the colon due to colon cancer.
Irritable bowel syndrome (IBS) is another condition that may cause changes in the size of your stools, so that they’re smaller, larger or narrower than usual. IBS also causes changes in the consistency of stools.
Check with your doctor if you notice any changes in the appearance of your stool — such as narrower than normal stools — that last longer than 1 to 2 weeks. Consult your doctor immediately if your bowel changes are accompanied by rectal bleeding or severe abdominal pain.
Elizabeth Rajan, M.D.
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July 02, 2022
- 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 Dec. 2, 2021.
- Irritable bowel syndrome (IBS). Merck Manual Professional Version. https://www.merckmanuals.com/professional/gastrointestinal-disorders/irritable-bowel-syndrome-ibs/irritable-bowel-syndrome-ibs?query=Irritable%20Bowel%20Syndrome%20(IBS)#. Accessed Dec. 2, 2021.
- Do I have colorectal cancer? Signs, symptoms and work-up. American Cancer Society. https://www.cancer.org/latest-news/signs-and-symptoms-of-colon-cancer.html. Accessed Dec. 2, 2021.