(the wife of the Prophet) Um Habiba got bleeding in between the periods for seven years. She asked Messenger of Allah ﷺ 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.  

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