<prompt> The following is true of Giardiasis except ?Complement fixation test is diagnosticStools contain only cystsHabitat is colonAll  <response>: Ans. is a i.e., Complement fixation test is diagnostic; b i.e., Stools contain only cysts; c i.e., Habitat is colon . Amongst the given option, only option d is true i.e., trophozoites and cysts are found in duodenum. About other options . The gold - standard for diagnosis of giardiasis is microscopic demonstration of the trophozoite, cyst or both in feces not C.F.T.. . Stools contain both cyst and trophozoite. . The normal habitat is duodenum and upper jejunum not colon. 