Surgery
Some people develop
diarrhea after stomach surgery (such as gastric
bypass 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 that can occur after gallbladder surgery. Another cause is
short bowel syndrome.
Certain Medical Conditions
A number of medical conditions are known to cause chronic diarrhea. These include:
Travel
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, sometimes, parasites. Traveler's diarrhea is a particular 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 this condition.