Fiberall Fiber Supplement contains psyllium, which is a soluble fiber. Psyllium promotes bowel regularity. It can be used regularly, as opposed to harsh stimulant laxatives which should only be used occasionally. Soluble fiber becomes gelatinous and sticky in water. It is not absorbed in the small bowel. It is broken down in the large bowel and becomes a food source for the bacteria that live in the colon.