I have two questions:
There are three different fluids that may create confusion about taharah.
Maniy or many المني which is fluid secreted by either male or female at the time of orgasm or climax. It comes from a man in a thick and white form while that which comes from a woman is thin and yellow (the Colour however could depend on the health of a person, for details refer to the fatwa from islamqa linked later).
... Man's discharge (i. e. sperm) is thick and white and the discharge of woman is thin and yellow ... (See Sahih Muslim, Sunan an-Nasa-i and Sunan ibn Majah)
And if one sees this fluid ghusl is necessary based on the statement:
... In case a woman sees that, she must take a bath. ...
(See for example in: Sahih Muslim -another version of the above hadith-, Sunan ibn Majah -same hadith as above-, Jami' at-Tirmidhi, Sunan abi Dawod and Sunan an-Nasa-i)
Further more there are some descriptions of its odour saying that it smells like urine (when dry), like dough and palm tree pollen.
Madhy المذي is what we may call pre-cum and is thin and white and sticky and comes out during foreplay, or when thinking about intercourse, or wanting it, or when looking, etc. it may come out without real arousal so usually one doesn't feel it. Imam an-Nawawi explaind it as follows:
Madhiy, on the other hand, is a sticky white fluid that is emitted when a person is thinking of or desiring intercourse. Its emission is not accompanied by feelings of pleasure, it does not gush out in spurts, and it is not followed by exhaustion. This may happen to men and women alike, although it is more common among women.
(Source islamqa #2458)
(See also Thinking about sex or talking about sex with someone of the opposite sex and after the liquid comes out?)
The ruling on madhiy is that one should perform wudu' and wash his private parts if one has experienced it based on:
"Perform ablution after washing your organ (penis)." (Sahih al-Bukhari)
Wadiy الودي this is a thik white fluid that comes out after passing urine (see islamqa #10540) and it has no odour which is the major difference between wadhiy and maniy. And the ruling on this is the ruling on urine.
So basically only maniy require ghusl while wadiy, madhiy and urine require wudu'. If one experienced madhiy it is recommended to wash his private parts too.
See also Do I need ghusl after after leaking from my penis when being affectionate with my wife?
Brothers, lets be very specific in describing the color/consistency of the fluids, so that there is no doubt in identifying and taking appropriate action to clense and become taahir. The Madhiy is Precum fluid and is a CLEAR (not white) thick, viscous and slimy fluid and its function is to provide lubrication and also to neutralise the acidity in the urinary tract. The Maniy is Semen and is a whitish(or slightly yellowish) , cloudy, thick, sticky and more viscous fluid that is ejaculated with involuntary spurts at the peak of orgasm followed by feeling of physical drain and slack. The Maniy contains sperms and other seminal, prostatic and other secretions responsible for enabling the swimming sperms with balanced moisture, pH levels and glucose for sustenance till these reach the female eggs.
