Purity: Purity of Remaining Blood in a Lawfully Slaughtered Animal
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 224
Blood that remains inside the body of an animal that has been slaughtered according to Islamic law is pure if a normal amount of blood has already come out, as stated in Ruling 94.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)