Diarrhea can result from intestinal contents moving too quickly or from food intolerances due to loss of certain enzymes.

腹泻的原因可以是肠内容物移动过快，或特定酶缺乏导致的食物不耐受。

It ends with the ileocecal valve, which prevents intestinal contents from going into the large intestine too quickly and the backward flow of material.

末端回肠结束于回盲瓣；回盲瓣可以防止肠内容物过快进入大肠以及肠内容物返流。

The third section is called the ileum, and it has tight intercellular junctions, allowing it to efficiently absorb fluid and begin concentrating the intestinal contents.

第三部分为回肠，有紧密的细胞间链接，使得回肠可以高效地吸收液体，浓缩肠内容物。