All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Scholars of Fiqh stated that pre-ejaculatory fluid is impure and also invalidates ablution. They provided two opinions regarding how to purify oneself or one's clothing from this fluid:
The first opinion: it has to be washed like other impurities.
The second opinion: it is enough to splash water over the affected areas.
The preponderant view is that it is better for the person who discharges this fluid in a normal way to follow the first opinion because it is the predominant and more cautious one. Those who experience hardship in washing it can follow the second opinion. It was narrated that Sahl ibn Hunayf said: "The pre-ejaculatory fluid bothered me a lot so as I was frequently making Ghusl. I complained to the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, who said, 'Making ablution is enough for you.' 'What about the drops falling on my garment, O Messenger of Allaah?' I asked. 'Take a handful of water and splash it over the areas smeared with it,' replied the Messenger of Allaah, sallallaahu ‘alayhi wa sallam." [At-Tirmithi]
This is regarding the fluid which afflicts the garment.
Discharge of pre-ejaculatory fluid necessitates washing the whole penis. This is according to the preponderant opinion of scholars. Some scholars are of the view that the scrotum has to be washed as well.
Since you experience hardship due to the frequent discharge of pre-ejaculatory fluid, it is enough for you to splash water over the place which you mostly believe to be smeared with it. This will be enough for you. However, washing is more cautious. Washing the penis for discharging the pre-ejaculatory is enough, and washing the scrotum as well is more cautious.
Allaah Knows best.