Amebiasis is an infection of the large intestine and sometimes the liver and other organs that is caused by the single-celled protozoan parasite Entamoeba histolytica, an ameba.
The amebas may be spread from person to person or through food or water.
People may have no symptoms or may have diarrhea, constipation, cramping abdominal pain, tenderness in the upper abdomen, and fever.
Doctors base the diagnosis on analysis of a stool sample and, if needed, other tests, such as colonoscopy or ultrasonography and blood tests.
People are given a drug that kills the amebas, followed by a drug that kills the dormant form (cysts) of the amebas in the large intestine.