Mason Natural Cascara Sagrada 450 mg with Calcium - Promotes Bowel Function, Gentle Constipation Relief, Improved Digestive Health, 100 Caplets At some point before the 1500s, Native American tribes on the upper West Coast discovered the bowel-cleansing properties of cascara sagrada and began to include it in their large chest of natural medicines. When Europeans arrived in the region, they quickly noticed the plant’s benefits and began to harvest and send the natural medicine back home. Four centuries later cascara accounted for 20% of sales in the category of stimulant laxatives in the U.S. The bark of cascara trees, like several other commercial plants in the category, contains anthraquinones, and terpene compounds which may be responsible for its effects on the intestinal tract, especially the colon. Aloe vera, Senna, and rhubarb root also demonstrate these properties.