Sūrat Al-Baqarah 2:184
A translation of this fatwā from Naseem Al-Sham:
What is the value of the kaffārah for the person who has been prevented from fasting by his doctor for health reasons? How does he carry it out, when and to whom?
Answer (Imam Muḥammad Tawfīq Ramaḍān):
Whoever has to break his fast due to illness and it is hoped that he will recover, all he has to do is make them up when he is able.
Whoever has to break his fast due to an illness from which he is not expected to recover has to donate the equivalent of approximately half a kilogramme of rice for each missed day, and when we say rice we mean the rice itself, not its monetary value.
 (tn): ‘those who are ill (N: the illness that permits not fasting being that which fasting would worsen, delay recovery from, or cause one considerable harm with; the same dispensation applying to someone who needs to take medicine during the day that breaks the fast and that he cannot delay taking until night.’ [Reliance of the Traveller (Beltsville, Maryland: Amana Publication, 1999), section i1.3(1), p.279]
 (tn): i.e. half a litre of food, which should be the staple crop of the country. Please see Reliance, section i1.33, p.290. According to Muʿjam Lughat al-Fuqahāʾ (Beirut: Dār Al-Nafāʾis, 1431/2010), s.v. Mudd, one mudd is equivalent to 0.543 kg, to be precise.