Acute diarrhea is usually related to a bacterial, viral, or parasitic infection. Chronic diarrhea is usually related to functional disorders such as irritable bowel syndrome or inflammatory bowel disease.
A few of the more common causes of diarrhea include the following:
Some people develop diarrhea after stomach surgery or removal of the gallbladder. The reason may be a change in how quickly food moves through the digestive system after stomach surgery or an increase in bile in the colon after gallbladder surgery.
People who visit foreign countries are at risk for traveler’s diarrhea, which is caused by eating food or drinking water contaminated with bacteria, viruses, or parasites. Traveler’s diarrhea can be a problem for people visiting developing countries. Visitors to the United States, Canada, most European countries, Japan, Australia, and New Zealand do not face much risk for traveler’s diarrhea.
In many cases, the cause of diarrhea cannot be found. As long as diarrhea goes away on its own, an extensive search for the cause is not usually necessary.