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Diarrhea (cont.)

Diarrhea Causes

Viral infections cause most cases of diarrhea and are typically associated with mild-to-moderate symptoms with frequent, watery bowel movements, abdominal cramps, and a low-grade fever. Viral diarrhea generally lasts approximately 3 to 7 days.

The following are the common causes of diarrhea caused by viral infections:

  • rotavirus is a common cause of diarrhea in infants;
  • norovirus (for example, Norwalk virus, caliciviruses) is the most common cause of epidemics of diarrhea among adults and schoolage children (for example, cruise ship infection, schools, nursing homes, day care facilities, and restaurants); and
  • adenovirus infections are common in all age groups.

Bacterial infections cause the more serious cases of diarrhea. Typically, infection with bacteria occurs from contaminated food or drinks (food poisoning). Bacterial infections also cause severe symptoms, often with vomiting, fever, and severe abdominal cramps or abdominal pain. Bowel movements occur frequently and may be watery.

The following are examples of diarrhea caused by bacterial infections:

  • In more serious cases, the stool may contain mucus, pus, or blood. Most of these infections are associated with local outbreaks of disease. Family members or others eating the same food may have similar illnesses.
  • Foreign travel is a common way for a person to contract traveler's diarrhea.
  • Campylobacter, salmonellae, and shigella organisms are the most common causes of bacterial diarrhea.
  • Less common causes are Escherichia coli (commonly called E coli) Yersinia, and listeria.
  • Use of antibiotics can lead to an overgrowth of Clostridium difficile (C diff) bacteria in the intestines.

Parasites cause infection of the digestive system by the use of contaminated water. Common parasitic causes of diarrhea include Giardia lamblia, Entamoeba histolytica, and Cryptosporidium.

Intestinal disorders or diseases including inflammatory bowel disease, irritable bowel syndrome (IBS), diverticulitis, microscopic colitis, and celiac disease can cause diarrhea.

Reaction to certain medications can cause diarrhea. Common medications include antibiotics, blood pressure medications, cancer drugs, gout medications, weight loss drugs, and antacids (especially those containing magnesium).

Intolerance to foods such as artificial sweeteners and lactose (the sugar found in milk) can cause diarrhea.

Medically Reviewed by a Doctor on 11/9/2012
Medical Editor:

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Diarrhea »

Acute diarrhea is defined as the abrupt onset of abnormally high fluid content in the stool (more than the normal value of approximately 10 mL/kg/d).

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