Are secretions mixed with blood after ghusl from nifas and before forty days considered nifas or not, and is prayer obligatory despite their presence?

The preponderant opinion is that the blood a woman sees during the forty-day post-childbirth period is nifas (definition) (postnatal bleeding). The purity that interrupts nifas is considered valid purity. If the bleeding continues beyond forty days, whatever exceeds this period is considered istihadha (irregular bleeding), unless it coincides with the woman's regular menstrual cycle.