Is washing the private part after urinating (Istinjaa`) a condition, and is it done with water and soap, or with water only?
Istinjaa` is obligatory for removing impurity, and it can be done with toilet paper, or a stone, or water. It is preferable to do Istinjaa` first with paper, or stone, or the like, then to wash the private part with water until making sure that the impurity has been removed. Using soap is not a condition, but there is no harm in doing so provided that it is washed off with water. It is also permissible to use either water, or paper if impurity is removed by any.
Do certain vaginal discharges and incontinence of urine nullify ablution, and should underwear be changed?
A person afflicted with constant impurity due to urinary incontinence and vaginal discharges is obliged to make ablution for every obligatory prayer when its time is due, and after removing Najaasah (impurity), and wearing a clean diaper. He/she is obliged to pray immediately even if the impurity is being released, and he/she is obliged to remake ablution, and the aforementioned for every obligatory prayer.
Is it permissible for a girl to wear colored contact lenses?
All Perfect Praise is due to Allah, The Lord of The Worlds.
Wearing colored contact lenses for medical treatment is permissible, and wearing them as an adornment is also permissible, provided that she isn`t seen while having them on by non-Mahrams. And Alalh Knows Best.
I missed fasting 30 days of the obligatory fast within the last 6 years and 20 days. How do I fast? And what should I do?
Missed fasting days must be made up, and it is permissible to make them up on non-consecutive days, as continuity is not required for making up missed fasts. Additionally, expiation (Fidya) must be given: feeding one needy person for each day if the makeup is delayed for one year. If the delay extends to two years, Fidya must be given to two needy people per day, and so on. And Allah Knows Best.