Her nifaas stopped, then the bleeding came back

If a woman’s nifaas stops before the forty days (after the birth) are over, she has to do ghusl and pray and fast Ramadaan, and it is permissible for her husband to have intercourse with her. If the bleeding resumes within the forty days (after the birth), then she has to stop praying and fasting, and it is forbidden for her husband to have intercourse with her, according to the more correct of the two scholarly views. She comes under the rulings on women in nifaas until either the nifaas stops or the forty days are over. If her nifaas stops before or on the fortieth day (after the birth), then she should do ghusl and start praying and fasting, and it is permissible for her husband to have intercourse with her. If the bleeding continues after the fortieth day (after the birth), then this is irregular bleeding and she should not stop praying and fasting because of it, rather she should pray and fast during Ramadaan, and it is permissible for her husband to have intercourse with her – as is the case with a woman with istihaadah (irregular, non-menstrual bleeding). She has to wash herself with water every time she uses the toilet, and use cotton pads etc. to absorb the bleeding, and she has to do wudoo’ for each and every prayer, because the Prophet (peace and blessings of Allaah be upon him) told women with istihaadah to do these things. But when her period comes, she should stop praying and fasting, and it is haraam for her husband to have intercourse with her until her period is over. And Allaah is the source of strength.