Is ghusl required if fluid is discharged but does not touch the underwear?

As soon as an impurity (such as urine or prostatic fluid) exits and becomes apparent, the area it soiled on the body or clothing must be washed. However, if what exited was semen, then ritual bathing (ghusl) is required if one of the signs of semen is present upon its exit while awake. The proof for this is the Prophet, peace and blessings be upon him, who said: "Yes, if she sees water." It is not a condition for this ruling to apply that the discharge has touched the underwear.