giardia lamblia protozoan, the causative agent of giardiasis,

giardia stomach microbe infectious microorganism microscopic digestive diarrhea intestine abdominal parasitic colon duodenum parasites intestinal ileum jejunum parasitology dangerous duodenalis intestinalis lambliasis cell human scientific lamblia protozoan 3d giardiasis background science parasite biology illustration colour trophozoite anatomy invasion disease microbiology medical flagella body infection small protozoa medicine microscopy microscope