Chia seeds
Chia seeds are the natural laxative in having the densest amount of fiber in it. One ounce of chia seeds, which is only 28 grams, contains almost 11 grams of fiber in it. Chia seeds are very convenient to use, and you can use them in your drinks, smoothies, breakfast cereal or plain water as well. The one-third portion of the fiber present in chia seeds comprises of soluble fibers. The soluble fiber forms a gel-like paste in the intestines and thus helps the passage of stool by providing the necessary lubrication.