fasting

معجم المصطلاحات الاسلامية - (ج 1 / ص 46)
 صيام
Fasting, from food and drink - and from sexual intercourse if you are married during daylight, from the first light of dawn until sunset. Also spelled as Saum. Fasting in the month of Ramadan is one of the Arkan (five pillars) of Islam. Allah Ta' ala has made it obligatory on every Muslim whether man or woman, with the exception of:
A person who is ill.

A person on ajourney of 16 Farsakhs (48 miles) or more.
A woman who is menstruating or who has just given birth. Once these situations no longer apply, the missed days must be compensated. The very young are exempted.The aged should fast, but if they find it difficult then they too are exempted and may feed poor people instead. See Holy Qur'an, Al-Baqara (2):184-185, 187.