Learn what causes chronic diarrhea and how to treat it.


What is Chronic Diarrhea?

Diarrhea that lasts for more than two weeks is considered persistent or chronic. In an otherwise healthy person, chronic diarrhea may be a nuisance. For someone who has a weak immune system, it could be a life-threatening illness.

What Causes Chronic Diarrhea?

There are many causes of chronic diarrhea; these may be different for children and adults. Causes of chronic diarrhea can be grouped into two categories: diarrhea caused by an infection and diarrhea not caused by an infection. Sometimes, the cause of chronic diarrhea remains unknown.

Diarrhea Caused by an Infection:

  • Parasites, such as Cryptosporidium parvum, Cyclospora cayetanensis, Entamoeba histolytica, Giardia lamblia, Microsporidia.
  • Bacteria, such as: Campylobacter, Clostridium difficile, Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Shigella.
  • Viral infections, such as: HIV, Rotavirus, Norwalk agent.

Diarrhea Not Caused by an Infection:

  • Antibiotics
  • High blood pressure medications
  • Cancer drugs
  • Crohn's diseases
  • Colitis
  • Diabetes, thyroid, and other endocrine diseases
  • Food additives (sorbitol, fructose, and others)
  • Food allergies
  • Previous surgery or radiation of the abdomen or gastrointestinal tract
  • Tumors
  • Reduced blood flow to the intestine
  • Heredity -- certain diseases occur more often in related family members
  • Travel

How is Chronic Diarrhea Diagnosed?

Diagnosis may be difficult and requires that your health-care provider take a careful history and perform a physical exam. The types of tests that your health-care provider orders will be based on your symptoms and history. Tests may include blood or stool tests; stool cultures may be used to test for bacteria. To detect parasites, CDC recommends that three or more stool samples be examined. Special stains may be required to look for some parasites. If these initial tests do not reveal the cause of your diarrhea, additional tests may include radiographs (x-rays) and endoscopy. Endoscopy is a procedure in which a tube is inserted into the mouth or rectum so that the doctor, usually a gastroenterologist, can look at the intestine from the inside.

Who is at Risk for Chronic Diarrhea?

Persons with severely weakened immune systems, such as those with HIV/AIDS, those taking certain types of chemotherapy, or persons who have recently received an organ transplant are at risk. So are travelers to developing countries where the water and food supply may be contaminated.

How is Chronic Diarrhea Treated?

The key to treating chronic diarrhea is to determine its cause.

  • Diarrhea caused by a bacterial infection can often be treated with antibiotics. However, the correct diagnosis must be made so the proper medication can be prescribed.
  • Diarrhea not caused by an infection is more difficult to diagnose and treat. Long-term medication or surgery may be required. Specific treatment for chronic diarrhea not caused by an infection should be discussed with your health-care provider.

For diarrhea whose cause has not been determined, follow these important treatment guidelines to relieve symptoms:

  • Prevent dehydration. Serious health problems can occur if you don't maintain your body's proper fluid levels. Diarrhea may become worse and hospitalization may be required if dehydration occurs. Many oral rehydration solutions such as Pedialyte and Oralyte are available at drugstores. Ask your pharmacist or health-care provider for the product best for you.
  • Do not drink beverages containing caffeine, such as tea, coffee, and soft drinks.
  • Do not drink alcohol; it causes dehydration.
  • Do not rely on sports drinks and broths alone to maintain adequate fluid balance. They should not be used to prevent SEVERE dehydration.
  • Maintain well-balanced nutrition. Doing so may help you recover more quickly.

How is Chronic Diarrhea Spread?

Chronic diarrhea caused by an infection can be spread by drinking water or eating food contaminated with stool. Close contact with a person who has diarrhea may also spread infection. This occurs when a person accidentally puts something that is contaminated with stool in or around his or her mouth. In general, chronic diarrhea not caused by an infection is not spread to other people.

How can Chronic Diarrhea be Prevented?

  • Drink clean or purified water.
  • Use proper food-handling techniques.
  • Maintain proper hand-washing habits.

Source: Centers for Disease Control and Prevention

Reviewed 2/02 by Jane Forester, MD

Originally published June 2001.

All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.

Healthy Kid