Question: How do I distinguish between semen (mani), pre-ejaculatory fluid (madhi), and post-urine fluid (wadi)?
Answer:
In the Name of Allah, the Most Merciful and Compassionate
You can distinguish between the different types of discharge by the details below:
(1) Semen (mani): a thick whitish liquid; when it comes forth with desire the desire subsides; its smell is like that of pollen. Female semen is thin and yellowish [Shurunbulali, Maraqi al-Falah].
(2) Pre-ejaculatory fluid (madhi): a thin clear fluid that comes out during sexual arousal. It does not spurt out and neither does one’s sexual arousal subside due because of it. Often one does not feel it coming out [Ibid.].
(3) Post-urinal fluid (wadi): a thick opaque liquid having no smell. It comes forth after urine and sometimes prior to it [Ibid.].
Residual Semen
Once one ejaculates semen, a ritual bath (ghusl) is obligatory. If after one performs the ritual bath, residual semen comes out – another ritual bath is due.
The exception to this rule is found if one does any action that would bring about reasonable surety that the semen has finished coming out. Examples of such actions are the following:
(a) urinating
(b) abundant walking
(c) sleeping
(d) waiting some time
… or the like.
In such a case one is excused from having to make another ritual bath; they must only make a new ablution (wudu)[Shurunbulali, Maraqi al-Falah].
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani