Skip to Content
Home > Wellness > Health Library > Mild, Moderate, or Severe Diarrhea
Diarrhea is described as an increase in the frequency of bowel
movements or a decrease in the consistency of stools that causes the discharge
of watery, loose stools. The severity of diarrhea is determined by the size and
number of stools passed within a period of time.
Severe diarrhea has many causes. Stomach flu (gastroenteritis) or
food poisoning may cause severe diarrhea. Drinking
untreated water that contains the Giardia lamblia parasite can cause diarrhea that develops 1 to
4 weeks later.
Severe diarrhea increases your risk of
dehydration by causing your body to lose large amounts
of fluid quickly. Be sure to increase your intake of fluids, such as
water or a
rehydration drink, and to watch for symptoms of
Persistent diarrhea can have many causes, including dietary changes,
irritable bowel syndrome, and certain
medicines. Occasionally, persistent diarrhea can be a
symptom of a more serious condition, such as a chronic infection,
inflammatory bowel disease, a
malabsorption syndrome, or
ByHealthwise StaffPrimary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency MedicineSpecialist Medical ReviewerH. Michael O'Connor, MD - Emergency Medicine
Current as ofAugust 21, 2015
Current as of:
August 21, 2015
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.