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.
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.
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.
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.
The key to treating chronic diarrhea is to determine its cause.
For diarrhea whose cause has not been determined, follow these important treatment guidelines to relieve symptoms:
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.
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.