Fiber can sometimes lead to constipation, especially if consumed in excessive amounts or if the body is not used to it. Insoluble fiber, which adds bulk to the stool, can help with constipation but may also worsen it if consumed too quickly or without adequate hydration.57 Soluble fiber, which absorbs water and forms a gel-like substance, can aid in softening the stool but might also contribute to constipation if the body does not tolerate it well.