I agree with kjones. Natural Vitality – Natural Calm (magnesium) is a great supplement worth trying. Magnesium is probably the best natural stool softener you can get. It tastes great as well.
Chronic constipation is actually one of my most severe symptoms. I use Natural Vitality Natural Calm and Acacia fiber daily. This helps noticeably.
I also have organic black coffee (not recommended on this forum) from time to time and it helps a lot.