Fiber is the part of fruits, vegetables and grains not digested by your body. A low-fiber diet restricts these foods. As a result, the amount of undigested material passing through your large intestine is limited and stool bulk is lessened.A low-fiber diet may be recommended for a number of conditions or situations. It is sometimes called a restricted-fiber diet.PurposeYour doctor may prescribe a low-fiber diet if: You have narrowing of the bowel...