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Teen Version

What is diarrhea?

Diarrhea is the sudden increase in the frequency and looseness of bowel movements. Mild diarrhea is the passage of a few loose or mushy bowel movements. Severe diarrhea is the passage of many watery bowel movements. The best indicator of the severity of the diarrhea is its frequency.

The main complication of diarrhea is dehydration from excessive loss of body fluids. Symptoms of dehydration are a dry mouth, the absence of tears, infrequent urination (for example, none in 12 hours), and a darker, concentrated urine. The main goal of diarrhea treatment is to prevent dehydration.

What causes diarrhea?

Diarrhea is usually caused by a viral infection of the lining of the intestines (gastroenteritis). Sometimes it is caused by bacteria or parasites. Bacterial diarrhea usually causes blood or lots of mucus in the stools. Occasionally a food allergy or drinking too much fruit juice may cause diarrhea. If you have just one or two loose bowel movements, the cause was probably something unusual you ate.

How long will it last?

Diarrhea from a viral infection usually lasts from several days to 2 weeks, regardless of the type of treatment. The main goal of therapy is to prevent dehydration by making sure you drink enough fluids to replace the fluids lost in the diarrhea. Don't expect a quick return to solid bowel movements.

How can I take care of myself?

  • Diet

    Eat a regular diet with a few simple changes:

    • Eat more foods containing starch since these are easily digested during diarrhea. Examples are cereals, breads, crackers, rice, mashed potatoes, and noodles.
    • Drink more water or diluted KOOL-Aid or diluted Gatorade
    • Avoid fruit juices because they make diarrhea worse.
    • Eat or drink less milk and milk products (except active-culture yogurt) for a few days.
    • Avoid beans or any other foods that cause loose bowel movements.

    You can go back to your normal diet 1 day after the diarrhea is gone, which is usually in 3 or 4 days.

  • Common mistakes

    The most dangerous myth is that the intestine should be "put to rest"; avoiding fluids can cause dehydration. There is no effective, safe drug for diarrhea. Extra fluids and diet therapy work best. Avoid fruit juices (especially apple and grape) because they make diarrhea worse.

  • Prevention

    Diarrhea is very contagious. Always wash your hands after using the toilet. This is crucial for keeping everyone in the family from getting diarrhea.

  • Vomiting with diarrhea

    If you vomit more than twice, treatment of the vomiting should take priority over the treatment of diarrhea until you have gone 8 hours without vomiting. Follow your doctor's recommended treatment for vomiting.

When should I call my health care provider?


  • You have signs of dehydration (no urine in more than 12 hours, very dry mouth, no tears).
  • Any blood appears in the diarrhea.
  • Your diarrhea is severe (more than 8 BMs in the last 8 hours).
  • The diarrhea is watery AND you have also vomited repeatedly.

Call during office hours if:

  • Mucus or pus appears in your BMs.
  • You have a fever for more than 3 days.
  • Mild diarrhea lasts more than 2 weeks.
  • You have other concerns or questions.
Written by B.D. Schmitt, M.D., author of "Your Child's Health," Bantam Books.
Published by McKesson Provider Technologies.
Last modified: 2006-10-12
Last reviewed: 2006-03-02
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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