The flagellates belong to the Magistophora and possess more than one flagellum.

  A cytosome may be present which helps in the identification of the species. 

The flagellates which are encountered in the intestinal tract are Giardia lamblia , Dientamoeba fragilis, Chilomastix mesnili, Trichomonas hominis, Retortamonas intestinalis and Enteromonas hominis, the latter 2 being less common. 

The trophozoites other than D. fragilis, are easily recognised in saline preparations by their motility.  However, accurate identification is done on a permanently stained faecal smear.  Cysts are more commonly seen than the trophozoite.