Definition:

Fiber, very simply, is the part of your food that you and your good bacteria and other microbes cannot break down and use (digest).  Since this part of your food cannot be digested and used, it will be passed out of your body when you empty your bowels.  Therefore, it will stay in your intestinal tract and help create a sensation to go have a bowel movement.  The fiber will also hold onto water and help keep your stool (also called feces and manure) from drying out.