If semen comes out after performing a ghusl
Question: After performing a ghusl, if there is seminal discharge, is it necessary for a man to re-perform the ghusl?

ANSWER
Let us explain it according to the four madhhabs:
In the Hanafî and Hanbalî Madhhabs, if the semen that leaves its place lustfully comes out later for any reason, even without lust, it will be necessary to make a ghusl. For this reason, it is necessaary to sleep for a while or to urinate and thereby to wash out the semen that has remained in the urethra.

It is necessary to perform a ghusl if semen leaves its place and comes out lustfully. As to the semen that leaves its place lustfully but comes out after one’s lust has subsided, it is necessary to perform a ghusl according to Imâm-i A’zam and Imâm-i Muhammad in this case. The fatwâ [an explanation on how to do Islam’s commandments] agrees with this. However, a ghusl is not necessary according to Imâm-i Abû Yûsuf. In case of a darûrat or necessity, it is permissible to follow the report of Imâm-i Abû Yûsuf. For example, if the performance of a ghusl is difficult at a house where one has been a guest or due to cold weather, in such cases, if a man who has a nocturnal emission in his dream wakes up and squeezes his penis so that the semen is prevented from coming out and if the semen comes out later after his lust has subsided, then it is not necessary to take a ghusl.

In the Shâfi’î Madhhab, after performing a ghusl, if semen comes out, one must make a ghusl again even if one has urinated. For it is necessary to re-perform the ghusl if the semen leaks even without lust in the Shâfi’î Madhhab.

In the Mâlikî Madhhab, if semen is discharged after performing a ghusl, one does not have to make a ghusl again even if one has not urinated because a ghusl is not necessary if semen issues without lust in the Mâlikî Madhhab.

But since a person who is in the Hanafî Madhhab but who imitates the Mâlikî Madhhab does not leave the Hanafî Madhhab, such a person has to wash out the semen that has remained in urethra by urinating.