In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
It is known that the doctor’s decision should be the most considerable opinion on such issues. So, as long as long the Hepatitis C patient has consulted a trustworthy doctor, he can follow his advice.
Answering your question, Sheikh Kifah Mustapha, the Imam and Director of The Prayer Center of Orland Park and representative for Dar El Fatwa of Lebanon in the US, states:
It is very clear in the Qur’an that sick people are exempted from fasting, “…and whoever is ill or on a journey – then an equal number of other days…” (Al-Baqarah 2:185)
So, in this case, if the doctor said the Hepatitis C patient should not fast, then he should not. And if he can make up for missed days later, it would be good. But if he cannot make up for it at all because of permanent illness, then he should feed a poor person for each missed day.
Almighty Allah knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.