Rhubarb is rich in fibre and includes sennoside A, which softens stools and promotes bowel motions.
Sweet potatoes are high in insoluble fiber, which can help avoid constipation by adding weight to stools.
Beans, peas, and lentils include both soluble and insoluble fiber, which can soften and bulk up the stool.
Chia seeds are high in soluble fibre, which softens and eases stool transit in the digestive tract by forming a gel-like consistency.
Flaxseeds are rich in both insoluble fiber and can help good bacteria develop in the stomach.
Whole grain rye bread is high in fiber and has been demonstrated to enhance bowel frequency while lowering intestinal transit time.
Oat bran is high in fibre and has been found in some earlier studies to enhance bowel function and decrease constipation.