Overview. Amebiasis is a parasitic infection of the intestines caused by the protozoan Entamoeba histolytica, or E. histolytica. The symptoms of amebiasis include loose stool, abdominal cramping, and stomach pain.However, most people with amebiasis won’t experience significant symptoms.mebiasis is common in tropical countries with underdeveloped sanitation. The Merck Manual states that amebiasis is most common in the Indian subcontinent, parts of Central and South America, and parts of Africa. It’s relatively rare in the United States. Persons at greatest risk for amebiasis include: