What is the ruling on the fasting of one who used to fast Ramadan without prayer, and who would not perform ghusl from janabah until the Dhuhr prayer? Is he required to make up those fasts? What is the ruling on his fasting if he felt thirsty and drank after returning from the Moroccan bath? And what should he do about the days he missed fasting due to illness, the number of which he no longer knows?

The validity of the fast of one who abstains from prayer out of laziness depends on the ruling concerning them: If it is said that they are a disbeliever (kafir), then their fast is not valid, and they are not required to make it up. However, if it is said that they are not a disbeliever (which is the preponderant opinion (mufta bihi)), then their fast is valid, and they are obligated to make up the missed prayers. Prayer while in a state of major ritual impurity (janabah) is not valid, and it must be made up. Drinking while fasting invalidates the fast, and making up that day is obligatory. If the thirst was life-threatening, there is no sin; otherwise, repentance is obligatory along with making up the day. If you began fasting and doubted whether you broke your fast or not, there is no make-up required, because the default assumption is that the fast remains valid. However, if you doubted whether you began fasting at all, the default assumption is that you did not, and making up the fast is obligatory.