Sunan Ibn Majah, Hadith 625

It was narrated from 'Adiyy bin Thabit, from his father, from his grandfather, that: The Prophet said: "The woman who experiences irregular non-menstrual bleeding should leave prayer during the days of her period, then she should take a bath, and perform ablution for each prayer, and she should fast and perform the prayer."

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَإِسْمَاعِيلُ بْنُ مُوسَى، قَالاَ حَدَّثَنَا شَرِيكٌ، عَنْ أَبِي الْيَقْظَانِ، عَنْ عَدِيِّ بْنِ ثَابِتٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ ‏ "‏ الْمُسْتَحَاضَةُ تَدَعُ الصَّلاَةَ أَيَّامَ أَقْرَائِهَا ثُمَّ تَغْتَسِلُ وَتَتَوَضَّأُ لِكُلِّ صَلاَةٍ وَتَصُومُ وَتُصَلِّي ‏" ‏ ‏.‏

sunnah.com