Diarrhea is a medical term used to describe a condition in which a child’s bowel movements increase in frequency, liquidity and volume. Diarrhea is usually described as loose, watery stools, and patients may also experience abdominal pain, abdominal cramping, fever, nausea or blood in the stool.

Diarrhea is extremely common in children, particularly before the age of 3 or 4. Only colds and other respiratory infections are conditions that strike children more often. Diarrhea usually lasts a few days and does not typically require treatment. However, diarrhea can become life-threatening when it causes severe dehydration, especially in the very young.

Different processes in the body may promote diarrhea. These include a failure of the intestines to absorb adequate nutrients and fluids during digestion, the release of too much fluid into the digestive tract or complications as the result of intestinal disorders.

Diarrhea can be short-term (acute) or long-term (chronic), and both types can range in severity. Acute diarrhea lasts less than four weeks. The most common cause of acute diarrhea is a viral infection (e.g., stomach flu) or bacteria or parasites consumed through contaminated food or water (e.g., food poisoning, traveler’s diarrhea).

Chronic diarrhea lasts for more than four weeks and may indicate a more serious problem, such as malabsorption of nutrients, inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS).

Because diarrhea is a symptom of other problems, treatment options will depend on the cause of the diarrhea. In children with a viral infection, the diarrhea is usually left untreated and resolves on its own within a few days. When the diarrhea is caused by certain foodborne bacteria or parasites (e.g., certain forms of Escherichia coli and salmonella), antibiotics may be required to treat the infection. For chronic conditions, such as IBD, specific medical treatment may be required.

If a child is dehydrated as a result of diarrhea, lost fluids and electrolytes will need to be replaced. For most children, this means drinking more fluids or an oral rehydration solution until the diarrhea resolves. Intravenous (into a vein) hydration may be necessary for some infants. Parents should check with a physician before using rehydration solutions or diarrhea medications in children.