What is the ruling on the fluid that is discharged after a period of feeling aroused, resembles semen, but is not discharged due to intercourse or a wet dream? And does it necessitate ghusl?

If the discharge is semen (maniyy), then ghusl (ritual bath) is obligatory upon its emission, based on the Prophet's (peace be upon him) saying: "Water (ghusl) is from water (semen)," and due to his (peace be upon him) command to the woman to perform ghusl if she sees water (semen). However, if it is not semen, but rather wadhi (thick white discharge) or madhiy (pre-seminal fluid), then only wudu (ablution) is obligatory after purifying the exit point and washing whatever affected the body and clothes. If you are in doubt and preponderant opinion favors one of the two matters, then act according to the preponderant opinion. But if you are in doubt between semen, madhiy, and wadhiy, then ghusl is not obligatory upon you.