The enterotest is not typically used to diagnose Giardia lamblia infection. Instead, the most common method for diagnosing Giardia lamblia is through a stool sample analysis. The stool sample is examined under a microscope to look for the presence of Giardia cysts or trophozoites. Additionally, there are other tests available, such as antigen tests and polymerase chain reaction (PCR) tests, which can also be used to detect Giardia lamblia infection.