If a person performs a ghusl and when he is done finds that the secretion is still coming out; does he has to do the ghusl again?
It is not necessary to repeat the process of ghusl (i.e. purification bath) in this case because the secretion is the remnant of the ejaculation you made ghusl for. However, you should wash the area again and perform wudu (i.e. ablution) if you are preparing to pray.
I hope I have clarified the issue.
God knows best.