It is narrated from Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) that Sayyiduna Uthman bin Affan (may Allah be pleased with him) used to suffer greatly from madhy (pre-seminal fluid), so he sent a man to the Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) said: "That is madhy, and every man emits madhy. Wash it with water, then perform ablution and pray."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17643