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Published on: 7/15/2026

What could cause my poop to be thinner than usual?

Yoshinori Abe

Reviewed by Yoshinori Abe, MD

Internal Medicine

Thin, narrow, or pencil-shaped poop isn't always a sign of a serious problem. Occasional changes in stool shape can result from diet, dehydration, or stress. However, persistently thin stools—especially when paired with symptoms like abdominal pain, blood in the stool, unexplained weight loss, or changes in bowel habits—may point to conditions such as hemorrhoids, IBS, or, less commonly, a bowel obstruction or colorectal issue. Tracking your symptoms and consulting a doctor is the safest way to rule out serious causes.

Because thin stools can stem from many possible causes, the fastest way to understand what may be behind your symptoms is to take a free, instant, online symptom check. In just a few minutes, you'll get personalized insights based on your specific symptoms, helping you decide whether to monitor at home, see a primary care provider, or seek urgent care. It's a smart, private first step toward clarity and confident next actions.

Reviewed for medical accuracy: 07/15/2026

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Important Next Steps

Discover why your stool looks thinnerLearn if thin poop needs careFind out what causes narrow stoolsSee OTC options for stool changesFind a doctor for bowel symptomsDiscover safe home remedies for thin stoolUnderstand if thin stool needs urgent care

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Explanation

Sometimes, poop can be thinner than usual, but this doesn't always mean something is wrong. According to the reference provided, thin or 'pencil thin' stool is not necessarily a sign of a serious medical issue.

Things to Consider:

  • Other Symptoms: If you have other symptoms like pain, blood in your stool, or a big change in your bathroom habits, it might be worth talking to a doctor.
  • Diet and Stress: Sometimes, changes in your diet or stress levels can affect the shape of your poop.

If you are worried about your poop being thinner than usual, it is a good idea to keep track of any other changes in your body. To help identify what might be causing your symptoms, try Ubie's free AI symptom checker and talk to a healthcare professional for advice.

(References)

  • Borhan-Manesh F. (2009). "Low caliber stool" and "pencil thin stool" are not signs of .... Digestive diseases and sciences, 18683051.

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