劍橋詞典

the last and narrowest part of the small intestine (= part of bowels after the stomach ), where substances from food are absorbed
回腸（胃部下方，小腸末端和最窄的一段，負(fù)責(zé)從食物中吸收營(yíng)養(yǎng)物質(zhì)） 返回 ileum