ENOfficial
It was narrated that 'Abdullah bin Arqam said: "The Messenger of Allah (ﷺ) said: 'If anyone of you needs to defecate and the immediate call to prayer (Iqamah) is given, let him start with (relieving himself).'"
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ الصَّبَّاحِ، أَنْبَأَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَبْدِ اللَّهِ بْنِ أَرْقَمَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " إِذَا أَرَادَ أَحَدُكُمُ الْغَائِطَ وَأُقِيمَتِ الصَّلاَةُ فَلْيَبْدَأْ بِهِ " .
sunnah.com