Idiom of the day :- Answer the call of nature
Usage, examples and definition of the Idiom :-
Teddy was on a walk in the forest when suddenly — and without warning — he had toanswer the call of nature. ‘I really must obey the call of nature.’ he whispered. Fortunately for Teddy, there was a WC nearby for to answer/obey the call of nature is to go to the bathroom.