Cascara sagrada and senna are both natural laxatives derived from trees and containing active compounds scientifically known as anthraquinones . Both are prepared and sold in whole bark and leaf form, powdered or in liquid tinctures. Cascara sagrada uses the bark of the tree, while senna uses leaves and pods. These herbs are equally unpleasant or bitter in taste.
Cascara sagrada was considered a gentle laxative by the Native Americans who first used it. The name means "sacred bark." The bark was traditionally peeled from the wood, collected in the spring and summer and allowed to dry in the shade. Although first used by Native Americans of the Pacific Northwest, the name was bestowed by Spanish priests in California.
Senna comes from a tropical tree also known as cassia and is not native to North America. Senna is considered a member of the legume family; the plant contains pods which bear small seeds inside.
Cascara sagrada and senna are stimulant laxatives. Their function is to assist easeful bowel evacuation. Stimulant laxatives work by causing the muscles in the large intestine to contract, evacuating the stool. They are recommended for short-term use and can cause dehydration and problems with the body's electrolyte balance if abused, according to the University of Maryland Medical Center. The hormone-like oil present in the cascara bark is responsible for the stimulating response. Senna has also been used in a paste form to treat skin infections such as ringworm and acne.
Cascara sagrada is a native North American plant. It can be found specifically from British Columbia to Washington. The bark grows naturally in woodlands, on mountain ridges and in canyons. Senna grows throughout Florida and the southeastern United States. It is native to tropical regions of Central and South America.
Acoording to the cascara sagrada guide published by Woodland's Publishing, "Cascara: Nature's Gentle Laxative," the herb has also been traditionally used to calm the nerves and promote sleep. It contains calcium, which can induce sleep and relaxation. Both cascara and senna are effective in relieving constipation within six hours of ingestion. Woodland Publishing's guide also notes that cascara may help expel parasites, due to the presence of a compound called rhein, which was used in Africa to expel worms.
The University of Maryland Medical Center advises that you use laxative herbs with caution because they may become less effective if used too often. Jackson/Siegelbaum Gastroenterology's website notes that a condition called melanosis coli may develop as a result of cascara or senna abuse. This is a gererally benign condition in which pigmented material is found in the lining of the colon. Melanosis coli is caused by chronic use of laxatives that contain cascara or senna.