A woman came to the Prophet ﷺ and said, "If anyone of us gets menses in her clothes then what should she do?" He replied, "She should (take hold of the soiled place), rub it and put it in the water and rub it in order to remove the traces of blood and then pour water over it. Then she can pray in it."  

جَاءَتِ امْرَأَةٌ النَّبِيَّ ﷺ فَقَالَتْ أَرَأَيْتَ إِحْدَانَا تَحِيضُ فِي الثَّوْبِ كَيْفَ تَصْنَعُ قَالَ تَحُتُّهُ ثُمَّ تَقْرُصُهُ بِالْمَاءِ وَتَنْضَحُهُ وَتُصَلِّي فِيهِ  

Fatima bint Abi Hubaish came to the Prophet ﷺ and said, "O Messenger of Allah ﷺ I get persistent bleeding from the uterus and do not become clean. Shall I give up my prayers?" Messenger of Allah ﷺ replied, "No, because it is from a blood vessel and not the menses. So when your real menses begins give up your prayers and when it has finished wash off the blood (take a bath) and offer your prayers." Hisham (the sub narrator) narrated that his father had also said, (the Prophet ﷺ told her): "Perform ablution for every prayer till the time of the next period comes."  

جَاءَتْ فَاطِمَةُ ابْنَةُ أَبِي حُبَيْشٍ إِلَى النَّبِيِّ ﷺ فَقَالَتْ يَا رَسُولَ اللَّهِ إِنِّي امْرَأَةٌ أُسْتَحَاضُ فَلاَ أَطْهُرُ أَفَأَدَعُ الصَّلاَةَ فَقَالَ رَسُولُ اللَّهِ ﷺ لاَ إِنَّمَا ذَلِكِ عِرْقٌ وَلَيْسَ بِحَيْضٍ فَإِذَا أَقْبَلَتْ حَيْضَتُكِ فَدَعِي الصَّلاَةَ وَإِذَا أَدْبَرَتْ فَاغْسِلِي عَنْكِ الدَّمَ ثُمَّ صَلِّي قَالَ وَقَالَ أَبِي ثُمَّ تَوَضَّئِي لِكُلِّ صَلاَةٍ حَتَّى يَجِيءَ ذَلِكَ الْوَقْتُ