How can one practice marital relations if menstruation is ongoing or if another form of it is present?

It is not permissible to have intercourse with one's wife during her menstrual period, due to the Almighty's saying: "And they ask you about menstruation. Say, 'It is an impurity, so keep away from women during menstruation. And do not approach them until they are pure.'" However, it is permissible to have intercourse with her during the days of istihada (post-menstrual bleeding) when she is observing fasts and performing prayers.