"Physician's Desk Reference for Herbal Medicines" states that the medicinal part of the Rhamnus plant is its dried bark. Indigenous to the Western region of North America, cascara was a folklore medicine used since the early 1800s by monks as a laxative. Its bark contains anthraquinone compounds that work on the mucosal lining of the intestine. According to "Sleisenger and Fordtran's Gastrointestinal and Liver Disease," 70 percent of people who use cascara sagrada as an anthraquinone laxative develop pseudomelanosis coli and yellow-brown urine. Take precautions when using any herbal supplement; consult your health provider before taking any form of the cascara species.
According to the Cleveland Clinic, cascara sagrada is used as a laxative in elderly and pediatric patients. After ingestion, cascara starts working on the colon within six to 10 hours. This plant stimulates the mucosal lining of the colon, producing an active secretion of electrolytes and water. Thus, the bowel contents increases, putting dilatation pressure on the colon, which in turn stimulates movement of the feces.
In 1939, cascara sagrada, also known as Rhamnus purshiana, was approved by the Food and Drug Administration (FDA) as a stimulant laxative, according to MDconsult.com. Cascara is commonly used by medical practitioners as a natural bowel preparation for colonoscopies or other intestinal procedures.
Hemorrhoids caused by aggressive "bearing down" can be treated by cascara, according the "Physicians Desk Reference for Herbal Medicines." Its laxative properties soften the stool, making it easier to pass through the colon. As a result, it effectively reduces the need for bowel straining and thereby decreases hemorrhoid manifestation.
When to Avoid Cascara Sagrada Bark
Contraindications include pregnancy, breast feeding, undiagnosed abdominal pain, bowel obstruction, irritable bowel syndrome, Crohn's disease, ulcerative colitis, fecal impaction, low blood potassium and appendicitis. Cascara also has a severe drug interaction with digoxin, which results in digoxin toxicity and death.