trophozoites interfere with the intestine's ability to absorb

nutrients and secrete digestive enzymes. 

Bacteria in the GI tract then digest those nutrients, producing gas as a

byproduct.

trophozoites interfere with the intestine's ability to excrete

nutrients into the lumen.  Protozoa in the GI tract then digest those nutrients, producing gas as a

byproduct.

cysts interfere with the intestine's ability to excrete

nutrients into the lumen.  Protozoa in the GI tract then digest those nutrients, producing gas as a

byproduct.

cysts interfere with the intestine's ability to absorb

nutrients and secrete digestive enzymes. 

Bacteria in the GI tract then digest those nutrients, producing gas as a

byproduct.