What necessitates making up for missed days and offering expiation in Ramadan, with evidence from the Quran and Sunnah, and is it restricted to sexual intercourse or does it include everything that intentionally reaches the stomach?

The Prophet, peace and blessings be upon him, explicitly stated the obligation of expiation (kaffarah) for a Bedouin who intentionally had intercourse with his wife during the daytime in Ramadan while fasting. The jurists agreed that the descriptions "Bedouin" and "his wife" are merely illustrative and do not affect the ruling. Thus, expiation is incumbent upon a Turk or a non-Arab who has intercourse with his wife, upon committing fornication (zina), and upon having intercourse with a slave woman. They also agreed that the regret of the one who had intercourse does not affect the obligation of expiation. Then, they differed on whether expiation is obligatory only for intercourse, or for intentionally violating the sanctity of Ramadan, even by eating and drinking. Shafi'i and Ahmad held the first view, while Abu Hanifa and Malik held the second. The correct view is the first, in accordance with the apparent meaning of the text, and because the principle is that one's liability is clear until an obligation is proven by clear evidence.