What is the ruling on one who, in his twenties, broke his fast for several days in Ramadan for several years without a valid excuse, and has now reached seventy years of age? Is he required to make up the fasts (qada') or feed the poor (it'am)?

If someone has missed fasting Ramadan for many years without denying its obligation, they are required to make up those fasts. They are not to resort to feeding the poor (fidya) unless they are permanently unable to fast, with no hope of recovery.