How can one's prayer be valid when isolated drops of urine are discharged, and does their discharge onto one's garment invalidate the prayer?

If your feeling of urine drops exiting is merely an illusion, then pay no attention to it. However, if it is real, then you must wash the area of impurity on the garment, perform istinja’ (washing the private parts), and repeat wudu’ (ablution). If you were in prayer, it is obligatory to interrupt it. Washing the impure spot is sufficient; changing clothes is not necessary. The Malikis make it easy regarding these drops if their exit is involuntary and occurs daily. If you are afflicted with sals (urinary incontinence), then you must take precautions by placing something on the private parts and perform wudu’ for each prayer after the time for it has begun.