How does Metamucil work as a laxative?
Metamucil contains a bulk-forming fibre without any chemical stimulants. The active ingredient, psyllium, is a harvested grain that absorbs and holds moisture. This causes the psyllium to swell, supplying the necessary bulk to help form an easily eliminated stool. Metamucil will not cause immediate evacuation but generally produces an effect in 12 to 72 hours.