Giardiasis and Diarrhea
September/October 2008 ISSN-1059-6518 Volume 21 Number 5
Giardia lamblia (Giardia lamblia) is a flagellated protozoan parasite that infects the small intestine causing diarrhea, bloating, and bad gas. People contract giardia when they consume contaminated food or water.
Giardia has a very simple life cycle. The dormant giardia cyst, ingested along with contaminated food or water, 
makes its home in the small intestine where the cyst hatches and changes into a trophozoite. (The trophozoites cause the illness—the un-hatched cysts do not.) The trophozoites then reproduce by binary fission (cell division) and the population grows.
