Entamoeba histolytica is an anaerobic, protozoan, intestinal parasite responsible for a disease called amoebiasis. It usually occurs in the large intestine and causes internal inflammation. It belongs to the genus Entamoeba and class Archamoeba. Amongst parasitic diseases, E. histolytica is one of the leading causes of morbidity and mortality in developing countries. E. histolytica is transmitted by ingestion of exit body containing cysts from faecally contaminated food and water or from hands. Due to their protective walls, the cysts can remain viable for several weeks in external environments. Species within this genus are small, single celled organisms with an anterior bulge representing a lobose pseudopod. The E. histolytica trophozoites are oblong and approximately 15-20µM in length, whereas the cysts are spherical and typically 12-15 µM in diameter. Entamoeba cysts are most commonly transmitted by ingestion so must be extremely robust to survive the hostile environment of the stomach. The cysts transform to trophozoites in the small intestine where they multiply by binary fission to then colonise the large intestine. They cause major calcium ion influx to the cells of the large intestine resulting in cell death and ulcer formation. The Trophozoites subsequently form new cysts which are excreted once more in faeces. Infection with E. histolytica generally causes mild symptoms such as abdominal pain, flatulence and diarrhoea, but more severe infections can lead to amoebosis. This is a condition encompassing amoebic dysentery characterized by severe abdominal pain, fever and blood in the faeces and less commonly amoebic liver abscesses.