Insoluble fibers that normally come with raw vegetable food products and are quite harsh. They act mechanically, scraping walls of your bowels clean. Insoluble fibers should better not be abused, as they can cause a traumatic effect or provoke hemorrhoids when overly consumed.
In a combination, these two types of can help you fight high blood sugar and cholesterol index.
A lot depends on the type of the fiber you consume. Soluble fiber, when mixed with liquids, absorbs them, increasing its initial size. Then, moving in your intestines, this mass collects toxic residue and removes it in a soft and non-traumatic way. It is suitable for people with sensitive bowels.
It's well known that consuming fiber is meant to help people suffering from constipation or bowel problems.
It's never actually that clear exactly how eating fiber-rich food helps.
The truth is that not all fiber will help your bowel movements. It's only the "insoluable" fiber from foods such as pasta, bread and other wheat products that bulks up your stool helping it pass through the intestine more quickly.