"Let her count the number of nights and says that she used to menstruate each month before this happened to her, and let her stop praying for that amount of time each month. Then when that is over let her perform Ghusl, then let her use a pad, and pray."
أَنَّ امْرَأَةً كَانَتْ تُهَرَاقُ الدَّمَ عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ فَاسْتَفْتَتْ لَهَا أُمُّ سَلَمَةَ رَسُولَ اللَّهِ ﷺ فَقَالَ لِتَنْظُرْ عَدَدَ اللَّيَالِي وَالأَيَّامِ الَّتِي كَانَتْ تَحِيضُ مِنَ الشَّهْرِ قَبْلَ أَنْ يُصِيبَهَا الَّذِي أَصَابَهَا فَلْتَتْرُكِ الصَّلاَةَ قَدْرَ ذَلِكَ مِنَ الشَّهْرِ فَإِذَا خَلَّفَتْ ذَلِكَ فَلْتَغْتَسِلْ ثُمَّ لْتَسْتَثْفِرْ ثُمَّ لْتُصَلِّي