Narrated 'Aisha:

(the wife of the Prophet) Um Habiba got bleeding in between the periods for seven years. She asked Allah's Apostle about it. He ordered her to take a bath (after the termination of actual periods) and added that it was (from) a blood vessel. So she used to take a bath for every prayer.

حَدَّثَنَا إِبْرَاهِيمُ بْنُ الْمُنْذِرِ، قَالَ حَدَّثَنَا مَعْنٌ، قَالَ حَدَّثَنِي ابْنُ أَبِي ذِئْبٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، وَعَنْ عَمْرَةَ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ ﷺ أَنَّ أُمَّ حَبِيبَةَ اسْتُحِيضَتْ سَبْعَ سِنِينَ، فَسَأَلَتْ رَسُولَ اللَّهِ ﷺ عَنْ ذَلِكَ، فَأَمَرَهَا أَنْ تَغْتَسِلَ فَقَالَ " هَذَا عِرْقٌ ". فَكَانَتْ تَغْتَسِلُ لِكُلِّ صَلاَةٍ.