Q. Blood transfusion for a Muslim patient from non-Muslim donors.
It is not unlawful for a blood transfusion to take place using blood from non-Muslim donors especially in cases of blood unavailability as is the case in many parts of Bangladesh. In al-Fatawa al-Hindiyya it has:
“It is permitted for a sick person to drink blood or urine or to eat carrion to treat himself if a Muslim doctor has advised him to do so because it will make him better and because there is no permissible alternative available…”
يجوز للعليل شرب الدم والبول وأكل الميتة للتداوي إذا أخبره طبيب مسلم أن شفاءه فيه ولم يجد من المباح ما يقوم مقامه
And Allah knows best.
 See al-Fatawa al-Hindiyya, 5:355.