Diagnosing Diarrhea - Diarrhea: Digestive Disorders

Content provided by the Faculty of the Harvard Medical School

Diagnosing diarrhea

The doctor will ask questions about your symptoms and try to determine whether the diarrhea is due to an organic problem, whether it's functional or chronic, or whether it's simply the result of a virus or bacteria and is likely to be short-lived. You may be asked questions about your habits, including drug or alcohol use. Alcohol abuse commonly results in diarrhea, for example, as does use of certain drugs, including cocaine.

The doctor will probably ask questions such as

• When did the diarrhea start?

• Have any other family members been sick?

• Have you recently traveled out of the country?

• Are you having abdominal pain? Fever? Chills?

• Is there blood in the stool?

• Is it worse when you are under stress?

• Do any specific foods make it worse?

• Do you drink coffee? Alcohol?

• What medications are you taking or have you taken recently?

If pus or blood in the stool accompanies diarrhea, or if there is fever, anemia, loss of appetite, or vomiting, it's not functional diarrhea.

For most people and for most mild episodes of diarrhea, no specific lab tests are required. But for more severe forms, or when symptoms of inflammation are present, the doctor will order stool tests to look for the presence of certain bacteria.

Blood can be drawn to test for hemoglobin, white cell count, and sedimentation rate. A sigmoidoscopy may also be performed. For people over 40, a colonoscopy or a barium enema may be ordered to check for organic diseases.

Doctors must also exclude the possibility of Crohn's disease, ulcerative colitis, or other serious illness, such as colon cancer. These are usually accompanied by blood in the stool, fever, or weight loss.

Last updated:	August 21, 2007