The Messenger of Allah ﷺ said: If any one of you offers prayer and feels a movement between his paddocks, but is doubtful whether or not his ablution broke, he should not cease praying unless he hears a sound or perceives a smell.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا كَانَ أَحَدُكُمْ فِي الصَّلاَةِ فَوَجَدَ حَرَكَةً فِي دُبُرِهِ أَحْدَثَ أَوْ لَمْ يُحْدِثْ فَأَشْكَلَ عَلَيْهِ فَلاَ يَنْصَرِفْ حَتَّى يَسْمَعَ صَوْتًا أَوْ يَجِدَ رِيحًا