My sister is suffering from bedwetting since early age. Now she is 20 years old, and all members of family know about this problem. We have been searching for a she-doctor or even a he-doctor to help us. Now, a young man next to us told me, as her brother, about his desire to marry my sister. Since this moment, I am very sad, feeling depressed, thanks to Allah anyway, and I asked him to give me some time to think. What shall I say to my mother who is sick with blood pressure and diabetes or my father who is very old? Not to mention other family troubles, even me, I was in a bad psychological state. Afterwards, I met our neighbor again not knowing what to tell him, hesitating, and confused, but in last I told him that this engagement can't happen currently, he replied: "If you don't agree, just tell me." I told him that all matter is that we have circumstances, then told him that my sister is suffering from a psychological problem, he asked about nature of this problem but I was unable to clarify more for him. Since that day, I am very regretful that I said so and can't sleep feeling guilty. After a while, I reached a very clever he-doctor and already medication has started, thanks to Allah there is a great improvement in her case, and now after medication and taking precautions my sister is rarely bedwetting after she had been making it daily. The case comes back only when she have a large amount of drinks. Now should I go to our neighbor, the polite young man, and clarify all things to him? Or I shouldn't talk about my sister problem?.
If there is any illness or defect that could affect married life or it could put one spouse off the other, it must be disclosed and it is haraam to conceal it.
Ibn al-Qayyim (may Allah have mercy on him) said: Every fault which puts the other spouse off, so that the purposes of marriage, namely compassion and love, cannot be achieved, mean that the spouse has the choice of annulling the marriage. (Zaad al-Ma’aad, 5/166)
See also the answer to question no. 111980.
Bedwetting is a fault that the suitor must be told about, but if your sister has recovered, or there is the hope that she will recover soon, then you do not have to inform her suitor.
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) was asked: There is a man who proposed marriage to a woman, and it is known that this woman has a physical defect, but this defect is hidden and is not obvious, and there is the hope that this defect may be cured, such as leprosy or vitiligo. Should the suitor be informed of that?
He replied: If a man proposes marriage to a woman who has a hidden defect, that some people know about, if the suitor asks about it, it is obligatory to tell him; this is clear. If he does not ask about it, then he should be told about it, because this comes under the heading of sincere advice, especially if there is no hope of it being corrected or cured. But if there is the hope that it may be corrected or cured, then it is less serious. But there are some things that may be cured, but the process is slow, if indeed it is even possible, such as leprosy, and to the best of my knowledge I don’t think it can be cured completely. Therefore a differentiation should be made between that which may be curable quickly, and that which is curable but will take some time.
End quote from Liqaa’aat al-Baab al-Maftooh@ah, 5/question no. 22
And Allah knows best.