3- Giardia Lamblia
Giardia lamblia Causes : Giardiasis in man especially children. Geog.Distribution: cosmopolitan. Habitat : duodenum, upper part of small intestine, bile.
Entamoeba histolytica Causes : Amoebiasis. Geog.Distribution: cosmopolitan Habitat: caecum and sigmoido- rectal region of man. Infective stage: Quadrinucleate.
Protozoa
