Dientamoeba fragilis is a parasite that lives in the large intestine of humans.
Infection occurs worldwide and is commonly diagnosed in the United States.
Loose stools, diarrhea, and abdominal cramping are the most common symptoms. Loss of weight and appetite, abdominal tenderness, and fatigue have also been reported among people who have D. fragilis . Many people have no symptoms at all. See your health care provider. Your health care provider will ask you to provide stool samples for testing.