The intestine; bowel—organs (small and large intestine) involved in digestion and absorption (anatomical term).
腸の動きが悪くて便秘になった。
My bowel movement was sluggish and I became constipated.
医者は腸の検査を勧めた。
The doctor recommended an intestinal examination.
腸内環境を整えるためにヨーグルトを食べている。
I eat yogurt to improve my intestinal flora.