I used to get emotional urethral discharges frequently and felt shy to ask Allah's Messenger (ﷺ) about it. So I requested Al-Miqdad bin Al-Aswad to ask (the Prophet (ﷺ) ) about it. Al-Miqdad asked him and he replied, "One has to perform ablution (after it)."
Sahih al-Bukhari Book 4, Hadith 44
← Previous Hadith My uncle said: The Prophet (ﷺ) said, "One should not leave his prayer unless he hears sound or smells something."

Sahih al-Bukhari Book 4, Hadith 43 Next Hadith → I asked `Uthman bin `Affan about a person who engaged in intercourse but did no discharge. `Uthman replied, "He should perform ablution like the one for an ordinary prayer but he must wash his penis." `Uthman added, "I heard it from Allah's Messenger (ﷺ)." I asked `Ali Az-Zubair, Talha and Ubai bin Ka`b about it and they, too, gave the same reply. (This order was canceled later on and taking a bath became necessary for such cases).

Sahih al-Bukhari Book 4, Hadith 45