This study will investigate the effectiveness of Polydextrose, a dietary fiber, at increasing Colonic Transit Time and decreasing the gastrointestinal symptoms of Functional Constipation. One quarter of the subjects will receive 12 g of Polydextrose daily, one quarter will receive 8 g of Polydextrose daily, one quarter will receive 4 g of Polydextrose daily and one quarter will receive a placebo daily.