giardiasis gi·ar·di·a·sis (jē'är-dī'ə-sĭs)
A condition in which the intenstines are infected with the protozoan Giardia lamblia. Also called lambliasis.
An intestinal infection caused by the protozoan Giardia lamblia. It is usually asymptomatic in humans but can cause diarrhea, nausea, and abdominal cramping. Giardiasis is most commonly transmitted by contaminated water and by direct contact among individuals in group settings.