This is a common protozoa to "my" gut. It is big, by comparison to other protozoa and produces cysts. It is hard to tell if these are problematic, because I have only seen attack by leukocytes one time.
The apicomplexan parasites collected previously, have been isolated in mucus, therefore have been associated with immune response, and deemed problematic.
Futhermore, they have been examined in culture for a variety of phases, and been evaluated.