Senna (Cassia angustifolia) is a small, peelable-bark shrub that grows in the upper Nile regions of Africa and the Arabian peninsula. Senna was used over 3500 years ago by ancient Egyptian physicians. According to a rare and amazing Egyptian medical papyrus, dating to the 16th century B.C., Senna was prescribed by the physicians for their distinguished patients. It was also used extensively by Arabian physicians, according to their 9th century A.D. writings. Senna was introduced to Europe before the Crusades and has been widely used ever since. The American Indians also employed the use of American Senna, a variety of the Eurpean species. Senna is often combined with various aromatic herbs.