Saying salaam before the imaam in cases of urgent need

If a person who is praying behind the imaam needs desperately to urinate or pass wind, and he is in the final Tashahhud, will his prayer still be valid if he says salaam before the imaam, after doing all the necessary parts or “pillars” of the prayer?

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who replied as follows:

Yes, his prayer will still be valid, because he has an excuse. And Allaah knows best.