[When is it permissible to uncover the severe private part (al-ʿawrah al-mughalaẓẓah) before a doctor?]

The answer – and Allah is the One who grants success and assistance – is that it is permissible to uncover the severe private part before the doctor in the following cases:
1. That the illness is dangerous, and there is fear that the patient may die because of it.
2. That the illness continues with the patient together with intense pain if he does not receive treatment.
3. That fractures or wounds occur around the private part whose treatment cannot be carried out except by a doctor.
And whatever resembles what we have mentioned, it is permissible in it to uncover the severe private part before the doctor.
The proof for that is what has been established and settled of the permissibility for the midwife to look at the woman’s private part at the time of birth, and also what has been established and settled of the permissibility for women to look at the private part of a virgin woman against whom fornication has been testified.
From this is what has been narrated from the Commander of the Believers (Peace be upon Him), in meaning: “I would not have carried out a hadd upon whom is the seal of Allah.” He said that concerning a virgin woman against whom they had testified to fornication, but she denied it and said that she was still a virgin. So he (Peace be upon Him) ordered the women to look at her private part… and so on.
In that there is what indicates the permissibility of uncovering the private part in order to repel harm, even if it has not reached the level of danger to life.
If it is said: Is it then permissible to uncover the private part for the sake of seeking a benefit – such as when a woman has inflammation in her womb which prevents the embryo from implanting, or when the female doctor places in her womb something that prevents pregnancy, or the like?
We say: If the woman is suffering from the pain of the inflammation, or she is harmed by repeated miscarriages because of the inflammation, or none of that has occurred but she fears that her husband will divorce her, or take another wife, or something similar that will cause her harm – then it is permissible for her to uncover her private part for treatment before the female doctor. Likewise, it is permissible for her to uncover herself before the female doctor so that she may place in her private part what prevents pregnancy, if she fears from becoming pregnant some harm to herself or to her small child.
And it is possible to infer this from what has been established and settled: that it is permissible for the witnesses of fornication to look at the private parts of the two fornicators so that they may bear witness to the act of fornication; their looking was permitted because of the public interests involved and the prevention of probable harm.
Yes, if a man is infertile and no child is born to him, is it permissible for him to uncover his private part before the doctor, and for semen to be extracted from him by medical means in order to know the cause of his infertility so that it may be treated?
It can be said: That is permissible in one situation, namely when the wife of that man insists upon the necessity of treating her husband’s infertility, otherwise she will leave him and separate from him and will not accept him as a husband; and the husband finds no answer to this demand except treatment for infertility, while he is harmed by separating from her because he is attached to her, loves her, and cannot be patient in her absence.
Or he is unable, if he separates from her, to marry another woman because of his poverty and lack of means; or he thinks that if he divorces her for this reason, women will not be pleased to accept him if he seeks their hand; or the like of that which leads to harm occurring because of the lack of a wife, or to falling into the prohibited. In that case it is permissible for him to undergo treatment with the doctor, because of His saying, Exalted: “Allah does not intend to make difficulty for you” [al-Mā’idah:6].
But if none of that harm occurs, then it is not permissible; rather, he must be patient with what has been decreed for him, and it is not permissible for him to enter into sin without necessity. And praise be to Allah, Lord of the worlds, and may Allah bless Muhammad and his family and grant them peace in great abundance.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2