If a Muslim man or woman prays in a garment on which there is some impurity, regardless of the type of garment, and he did not remember that until after he had finished praying, then his prayer is valid according to the correct opinion.

The jurists agree that if pus is expelled by the human body, it is impure, because it comes under the heading of unclean things (Al-khaba’ith: unclean, impure, evil things).

Flowing blood is impure according to scholarly consensus. That is indicated by clear evidence from the Quran and Sunnah.