Diarrhea is usually caused by a virus, bacteria or, sometimes, contaminated food. Less often, it can be a sign of another condition, such as inflammatory bowel disease or irritable bowel syndrome.
Symptoms include frequent, loose, watery stools and belly pain.
Diarrhea usually clears on its own. Some infections may need antibiotics. Serious diarrhea can cause enough dehydration to require IV fluids.