It is narrated from Sayyiduna Ali (may Allah be pleased with him), he says: I used to have a lot of madhiy (pre-seminal fluid), regarding my question about it, the Messenger of Allah (peace and blessings be upon him) said: Ghusl is required for semen, and wudu is required for madhiy.
Hadith Takhrij«أخرجه البخاري: 132، 178، ومسلم: 303 بلفظ قريب منه ، (انظر مسند أحمد ترقيم الرسالة: 662 ترقیم بيت الأفكار الدولية: 662»
Brief Explanation
Benefits: … Ablution (wudu) is nullified by madhiy (pre-seminal fluid); the remaining rulings regarding madhiy have already been mentioned in the benefits of Hadith number (465).