What is the ruling on the yellow fluid that is discharged after feeling aroused, and is ghusl or wudu required if it is discharged at the time of Dhuhr prayer?

You are not required to perform ghusl (ritual bath) unless you are certain that semen has been discharged, as the mere feeling of excitement does not necessitate its exit. If you are unsure whether the discharge is semen or something else, the fatwa we adhere to is that you have the choice to consider it whatever you wish. It is advisable to avoid causes of arousal, to fast frequently, and to lower your gaze.