
Actually, it is possible to eat fiber foods and still constantly. That can happen when you eat food mostly rich in one type of fiber, and not in the other.
For example, if you mainly eat berries, corn and integral rice for fiber, insoluble fiber is being mostly obtained. That type of fiber is what we think as «erogy» and increases poop, so it is easier to pass.
But you also need soluble fiber every day, of the type that forms a gel and softens the poop. Soluble fiber sources include beans, oats, carrots and skin on apples and pears.