由贾第虫感染小肠引起感染性腹泻的例子。小的梨形滋养体在十二指肠内，变成有感染性的包囊后释放出来。它会产生水样腹泻。感染性腹泻诊断的检查是大便检查寻找卵和寄生虫。
This is an example of infectious diarrhea due to Giardia lamblia infection of the small intestine. The small pear-shaped trophozoites live in the duodenum and become infective cysts that are excreted. They produce a watery diarrhea. A useful test for diagnosis of infectious diarrheas is stool examination for ova and parasites.
