腹が下る
to have an attack of diarrhoea―have loose bowels―(下剤をかけてなら)―purge the bowels―evacuate the bowels―open the bowels―loosen the bowels
to have one's stomach full
to have a secret understanding with each other
a stomach
腹が弛んだ
the condition of the stomach and the intestines
腹がへった
Be careful what you put in your belly.