Among routine microscopic methods, the permanent stained smear is generally the best choice; although it can be seen on wet mounts, it is difficult to identify. As mentioned previously, several forms or stages exist. The most commonly described "body form" or "vacuolar form" is generally round, varies from 6–40 μm, and has a large central body resembling a vacuole.
ELISA is the antigenic detection method for stool currently in use. ELISA and fluorescent antibody techniques have also been developed to detect serum antibodies.
