evacuate one's bowels
Euph. to defecate. After taking a jog around the block, Jill felt the need to evacuate her bowels. I am afraid my little boy is sick. He has not evacuated his bowels for several days.
evacuate someone (from something) (to something)
to remove someone from something or some place to another thing or place, as in an emergency. They had to evacuate everyone from the subway station to a nearby building. The rescuers evacuated the people from the flames.