Q: If a woman with postnatal bleeding becomes pure within a week, then she fasts with the Muslims during Ramadhaan for a number of days, then her bleeding returns, does she break her fast in this situation? Does she have to make up for the days that she fasted and the days that she broke her fast?
A: If the woman with postnatal bleeding becomes pure within 40 days and she fasts some days, then bleeding returns during the days, her fast is correct. She must leave off the prayer and fasting during during the days that her bleeding returned because it is postnatal bleeding – until she becomes pure and completes the 40 days.
When she completes the 40 days she must bathe, even if she does not think that she is pure, because the 40 days is the end of the postnatal bleeding according to the correct view between the two opinions of the scholars. After that she must make wudhoo for the time of each prayer until the bleeding stops, as the Prophet (sallallaahu ‘alaihi wa sallam) commanded the woman with a prolonged flow of menstrual blood to do. Her husband may enjoy sexual relations with her after the 40 days even if she does not think that she is pure. This is because the (postnatal) blood and the situation mentioned is not (postnatal) blood that does not prevent the prayer and fasting, nor does it prevent the husband from from his sexual enjoyment with his wife. However, if after the 40 days the bleeding coincides with her normal time of menstruation, then she leaves off the prayer and fasting and she considers it a menstrual cycle, and Allaah is the Giver of success.
Shaykh Ibn Baaz (rahimahullaah)
Fataawa Islaamiyyah Vol. #3 Page 298-299
“If you are able, then be a scholar; if you are not able then be a student;
And if you are not able, then love them; and if you are not able, then do not hate them.”
‘Umar Ibn ‘Abdil ‘Azeez