Final answer:
Giardia lamblia is a zoonotic protozoal agent that causes diarrhea and GI cramping in humans. It enters the body through contaminated food or water and attaches to the lining of the small intestine. This can lead to symptoms such as diarrhea, abdominal pain, and fever.
Step-by-step explanation:
One of the zoonotic protozoal agents that cause diarrhea and GI cramping in humans is Giardia lamblia. This flagellate protozoa causes giardiasis and enters the body through contaminated food or water that has been contaminated by feces of infected people or animals. It attaches to the lining of the small intestine, preventing the host from absorbing nutrients and leading to symptoms such as diarrhea, abdominal pain, and fever. It typically spreads through a fecal-oral route, commonly through contaminated food or water.