What are the healthiest foods to eat when someone has problems with stomach pain and constipation?

A friend of mine overseas (lebanon) has trouble with stomach pain and constipation. I am 100% sure its diet related. Can anyone point me to a site or information that will give me a diet that could be followed in Beirut?
Are there any health food stores in Beirut?

Your friend should avoid greasy,high fat food and acidic food like citrus juices, carbonated drinks. A tablespoon of coriander seeds is a natural home remedy for stomach aches, to be eaten after meals. More home remedies for stomach ache at http://www.aches.in/homeremediesstomachache.html