Recent Blog Articles
Cardiovascular safety from prostate cancer drugs remains uncertain
Rising alcohol use among older adults
Easily distracted? Try meditation
Harvard Health Ad Watch: Can a wearable device reduce stress?
Listening to your hunger cues
Does your child need to bathe every day?
Can flavonoids help fend off forgetfulness?
Can physical or cognitive activity prevent dementia?
Wondering how much your medical care will cost? New rules could help
Long-lasting healthy changes: Doable and worthwhile
What Is It?
Diarrhea is more frequent and more liquid bowel movements than normal. There are many causes. Diarrhea often is caused by an infection with bacteria, viruses or a parasite. Bacteria cause diarrhea either by invading the intestine or by producing a toxin that makes the intestine secrete more water. When the diarrhea is caused by food contaminated with bacteria or parasites, people often refer to this as food poisoning.
Other causes of diarrhea include:
- Irritable bowel syndrome, especially during times of increased stress
- Side effects from medications, such as antibiotics and magnesium-containing antacids
- Overuse of laxatives
- Inflammation of the lowest part of the intestine (ulcerative colitis or Crohn's disease).
People with diarrhea usually have loose, watery stools. Less commonly, people pass frequent, small amounts of loose stool with mucous and blood. Other symptoms can include:
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.