Occasions when husband or wife can nullify Nikah
2389. If the husband comes to know after Nikah that his wife had, at the time of Nikah, any one of the following six deficiencies, he can annul the marriage:
Insanity, even if it is intermittent.
Being crippled, even if it is not to the extent of immobility.
Presence of flesh or a bone in the woman's uterus, which may or may not obstruct sexual intercourse or pregnancy. And if the husband finds that the wife at the time of Nikah, suffered from 'Ifdha' - meaning that her urinary and menstrual tract have been one, or her menstrual passage and rectum have been one, he cannot annul the marriage. As an obligatory precaution, he will have to pronounce talaq if he wants to dissolve the marriage.
2390. A woman can annul the Nikah in the following cases, without obtaining divorce:
If she comes to know that her husband has no male organ.
If she finds that his penis has been cut off before or after the sexual intercourse.
If he suffers from a disease which disables him from sexual intercourse, even if that disease was contracted after the Nikah, or before or after the sexual intercourse.
2390. In the following situations, if a wife refuses to continue with the matrimony and wishes to dissolve the marriage, then as a matter of precaution, the husband or his guardian will solemnise the divorce:
If she comes to know after the Nikah, that the husband was insane at the time of Nikah; or if he becomes insane after the Nikah, before or after consummation of the marriage.
If she finds out that at the time of Nikah, the husband had been castrated.
If she learns that he suffered at the time of Nikah from leprosy or leucoderma.
Note: And if the husband is incapable of sexual intercourse, and she wishes to annul the marriage, it will be necessary for her to approach the Mujtahid or his representative, who may allow the husband a period of one year, and if it is found that he was not able to have sexual intercourse with her or with any other woman, the wife can annul the marriage.
2391. If the wife annuls the marriage because of the husband's inability
to have sexual intercourse, the husband should give her half of her Mahr. But,
if the man or the wife annuls the marriage because of one of the other deficiencies
enumerated above, and if the marriage has not been consummated, he will not
be liable for anything.
But if the marriage was consummated, he should pay her full Mahr. If the husband annuls the marriage due to the deficiencies mentioned in rule 2389, he will not be liable for anything if he has not had sexual intercourse with her. But if he has had sexual relation with her, then he has to pay full Mahr.