amoebiasis due to Entamoeba histolytica
A parasitic disease caused by the protozoa, Entamoeba histolytica, mainly occurring in tropical regions after the ingestion of an amoebic cyst, and resulting in clinical manifestations that may range from an asymptomatic state to amoebic colitis (violent abdominal pain, a painful contracted feeling around the anal sphincter, blood and mucus in the stools but without the presence of fever), or amoebic liver abscesses (fever, chills, abdominal pain, weight loss, hepatomegaly) that can be fatal if not immediately treated. Extraintestinal involvement elsewhere (i.e. thoracic, hepatic) is extremely rare.