Praise be to Allaah.
If it is necessary to carry out a blood transfusion, there is no sin on the patient, the doctors or the donor, because of the following:
Allaah says (interpretation of the meaning): “… and if anyone saved a life, it would be as if he saved the life of all mankind…” [al-Maa’idah 5:32]. This aayah indicates the virtue of being the cause of saving the life of someone whom it is forbidden to kill, and there is no doubt that the doctors and blood donors are among the causes of saving the life of patients who are at risk of dying if a blood transfusion is not carried out.
The guidelines of Islamic sharee’ah dictate that donating blood should be permitted, because one of its principles is that in cases of necessity, things that are ordinarily forbidden are permitted, and that ways should be found to ease hardship. The sick person is certainly in a hardship situation, and is compelled by necessity. The hardship he is facing could lead to his death, so it is permissible for him to receive a blood transfusion. (For more details on the issue of donating blood, see Question #2320).
As regards the question of whether wudoo’ is broken by the flowing of blood, this is an issue concerning which the scholars, may Allaah have mercy on them, differed. Those who think that bleeding breaks wudoo’ quote as evidence the hadeeth of Abu’l-Darda’ (may Allaah be pleased with him): “The Prophet (peace and blessings of Allaah be upon him) vomited, then did wudoo’.” They drew an analogy between vomit and blood, because both are naajis (impure) when they come out of the body.
This hadeeth was narrated by Ahmad (4/449), Abu Dawood (2981) and al-Tirmidhi (87), who said: “More than one of the scholars among the Companions of the Prophet (peace and blessings of Allaah be upon him) and others among the Taabi’een thought that wudoo’ should be done after vomiting or having a nosebleed. This is the opinion of Sufyaan al-Thawri, Ibn al-Mubaarak, Ahmad and Ishaaq. Some scholars said that wudoo’ is not necessary after vomiting or having a nosebleed. This is the opinion of Maalik and al-Shaafa’i.” This was also narrated as being the opinion of Ahmad. Al-Baghawi said: It is the opinion of most of the Sahaabah and Taabi’een.”
The most correct view is that bleeding does not break one’s wudoo’, although it is preferable (mustahabb) to make wudoo’ after bleeding. The evidence for this is as follows:
Wudoo’ is considered to be valid until there is proof that something breaks it. There is no proof narrated from the Prophet (peace and blessings of Allaah be upon him) that bleeding breaks wudoo’, hence Imaam al-Nawawi (may Allaah have mercy on him) said, “There is no proof whatsoever that the Prophet (peace and blessings of Allaah be upon him) made it obligatory to do wudoo’ because of that (bleeding).” Shaykh Ibn Sa’di (may Allaah have mercy on him) said, the correct opinion is that bleeding and vomiting, etc., do not break wudoo’, whether they are large or small in volume, because there is no evidence to proof that they break wudoo’, and the guiding principle is that wudoo’ remains valid.
One cannot draw an analogy between blood and anything else, because the reasons behind them are not the same.
The idea that bleeding breaks wudoo’ is contrary to what was reported from the salaf (early generations), for example, ‘Umar ibn al-Khattaab (may Allaah be pleased with him) continued to pray although his wound was pouring with blood. Al-Hasan al-Basri (may Allaah have mercy on him) said, “The Muslims continue to pray even when they are wounded.”
The fact that the Prophet (peace and blessings of Allaah be upon him) did wudoo’ after he vomited does not indicate that it is obligatory to do so, because the rules of fiqh say that the mere fact that he did something, unless it was accompanied by a command to do it, does not make it obligatory. All that this proves is that it is good to follow the example of the Prophet (peace and blessings of Allaah be upon him) in this instance. Hence Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said: “Doing wudoo’ after cupping and vomiting is mustahabb and is good.”
To sum up the above: It is mustahabb (preferable) for a blood donor to do wudoo’ after giving blood, but if he does not do wudoo’, it is still OK.
And Allaah knows best.
On the issue of donation, see:
Al-Mukhtaaraat al-Jaliyyah by Shaykh ‘Abd al-Rahman ibn Sa’di, 327; Ahkaam al-At’imah fi’l-Sharee’ah by Dr. ‘Abd-Allaah al-Tareeqi, 411, Majallat al-Majma’ al-Fiqhi, issue 1, p. 32; Naql al-Damm wa Ahkaamuhu by al-Saafi, 27; Ahkaam al-Jiraahah al-Tibbiyah, by Dr. al-Shanqeeti, 580.
On the issue of bleeding breaking wudoo’, see:
Majmoo’ al-Fataawa, 20/526; Sharh ‘Amdat al-Fiqh, by Ibn Taymiyah, 1/295; al-Mughni by Ibn Qudaamah, 1/234; Tawdeeh al-Ahkaam by al-Bassaam, 1/239; al-Sharh al-Mumti’ by Ibn ‘Uthaymeen, 1/221.