"That is (bleeding from) a vein, so when the time of menstruation comes, stop praying, and when it goes, then wash the blood from yourself then pray."  

عَنْ فَاطِمَةَ بِنْتِ قَيْسٍ مِنْ بَنِي أَسَدِ قُرَيْشٍ أَنَّهَا أَتَتِ النَّبِيَّ ﷺ فَذَكَرَتْ أَنَّهَا تُسْتَحَاضُ فَزَعَمَتْ أَنَّهُ قَالَ لَهَا إِنَّمَا ذَلِكِ عِرْقٌ فَإِذَا أَقْبَلَتِ الْحَيْضَةُ فَدَعِي الصَّلاَةَ وَإِذَا أَدْبَرَتْ فَاغْسِلِي عَنْكِ الدَّمَ ثُمَّ صَلِّي  

"When the time of menstruation comes, stop praying, and when it goes, perform Ghusl."  

أَنَّ النَّبِيَّ ﷺ قَالَ إِذَا أَقْبَلَتِ الْحَيْضَةُ فَاتْرُكِي الصَّلاَةَ وَإِذَا أَدْبَرَتْ فَاغْتَسِلِي  

"Umm Habibah bint Jahsh suffered Istihadah (non-menstrual vaginal bleeding) for seven years. She complained about that to the Messenger of Allah ﷺ and the Messenger of Allah ﷺ said: 'That is not menstruation; rather that is (bleeding from) a vein, so perform Ghusl then pray.'"  

قَالَتِ اسْتُحِيضَتْ أُمُّ حَبِيبَةَ بِنْتُ جَحْشٍ سَبْعَ سِنِينَ فَاشْتَكَتْ ذَلِكَ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَ رَسُولُ اللَّهِ ﷺ إِنَّ هَذِهِ لَيْسَتْ بِالْحَيْضَةِ وَلَكِنْ هَذَا عِرْقٌ فَاغْتَسِلِي ثُمَّ صَلِّي