Does an internal medical examination for a woman affect her fast?
An internal medical examination for a woman invalidates the fast because it involves the entry of a foreign object into the body cavity (jauf) while fasting.
In this case, the woman must refrain from eating and drinking for the rest of the day out of respect for Ramadan and make up for the missed fast after Ramadan.
Such an examination should be avoided in Ramadan and other months unless absolutely necessary, as exposing the private parts is only permissible in cases of necessity.
If necessary, a woman should seek a Muslim female doctor first. If one is unavailable, she may see a female doctor from the People of the Book (Jews and Christians). If neither is available, she may consult a trustworthy and competent Muslim male doctor.
What is the ruling on one who sees moisture on his clothes and doubts whether it is semen or pre-seminal fluid (madhy)?
Whoever finds moisture upon waking from sleep and doubts whether it is semen or madhy, and cannot distinguish between them, he may choose between them and act according to his choice. If he wishes, he can consider it semen and perform the ritual bath, or consider it madhy, perform ablution, and wash what it has soiled. This is because if he fulfills the requirement of one of them, he is definitively free from it, and the default is his innocence from the other. And Allah the Almighty knows best.
Is it permissible for an elderly person, a pregnant woman, or someone with a chronic illness to pay fidyah before Ramadan begins?
It is not permissible for an elderly person, a pregnant woman, or someone with a chronic illness to pay fidyah before Ramadan begins.
Additionally, it is not allowed to pay fidyah for more than one day in advance, because fidyah is a substitute for fasting, and fasting is not yet obligatory at that time.
However, it is permissible to pay fidyah for a single day in advance, by analogy with paying zakat up to one year in advance.
Can someone who begins a voluntary fast break it?
It is preferable for someone who begins an act of worship not to break it.
Allah the Exalted has said {what means}: "and let not your [good] deeds come to nought!" [Muhammad/33].
However, if a person starts a voluntary fast (nafl) and needs to break it, they are going against what is preferable, but there is no sin upon them.