ANSWER: 

Madhi is impure and requires running water on it, along with renewal of wudu while Mani is pure (comes out in a gushing manner, accompanied by desire and a feeling of sensation and pleasure) and requires ghusl. 

If you saw a small amount of discharge, this is most likely madhi and it is impure.

Sheikh I heard that Man’i is pure. If after waking up from sleep, I see Man’i at the tip of my private part, then I touch the place (the tip of the private part), some of this Man’i got on my fingers. Is the Man’i on my finger also pure? Because, I think of it this way that, some urine was obviously somewhere in the veins of the private part (or the main channel through which urine comes out), and those urine must have come out with the Man’i, thus making the Man’i impure.