Definition & Facts for Diarrhea

What is diarrhea?

Diarrhea is loose, watery stools three or more times a day. Diarrhea may be acute, persistent, or chronic:

  • Acute diarrhea is a common problem that typically lasts 1 or 2 days and goes away on its own.

  • Persistent diarrhea lasts longer than 2 weeks and less than 4 weeks.

  • Chronic diarrhea lasts at least 4 weeks. Chronic diarrhea symptoms may be continual or may come and go.

How common is diarrhea?

Diarrhea is a common problem. Acute diarrhea is more common than persistent or chronic diarrhea. Researchers estimate that about 179 million cases of acute diarrhea occur in the United States each year.1

What are the complications of diarrhea?


Diarrhea may cause dehydration, which means your body lacks enough fluid and electrolytes to work properly. Your body loses more fluid and electrolytes in loose stools than solid stools. See a list of the symptoms of dehydration.


Diarrhea may cause malabsorption. If people do not absorb enough nutrients from the food they eat, they may become malnourished. Certain conditions that cause chronic diarrhea—such as infections, food allergies and intolerances, and certain digestive tract problems—may also cause malabsorption. See a list of the symptoms of malabsorption.


Last Reviewed November 2016
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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.