ANSWER:

If he is exempted from fasting according to the instructions of a trusted Muslim doctor and the doctors say that he would never be able to fast again till the rest of his life, he can feed one person after the day of Ramadan is over. You must not give it in advance. But if the doctors say that he will recover in few years time, he must not feed and must wait until he is recovered and then make up all these missed days. 

QUESTION: My brother gets unbearably painful kidney stones often. It worsened during Ramadan last year due to dehydration. Is he exempted from fasting and can we give fidya instead?