Senna is a large genus of flowering plants in the legume family Fabaceae, and the subfamily Caesalpinioideae and the tribe Cassieae. This diverse genus is native throughout the tropics, with a small number of species in temperate regions. The number of species is estimated to be from about 260 to 350. About 50 species of Senna are known in cultivation. The leaves and the fruit of the plant are used to make medicine.
Senna contains many chemicals called sennosides. Sennosides irritate the lining of the bowel, which causes a laxative effect.
Senna is an FDA-approved over-the-counter (OTC) laxative. It is used to treat constipation and also to clear the bowel before diagnostic tests such as colonoscopy. Senna is also used for irritable bowel syndrome (IBS), anal or rectal surgery, tears in the lining of the anus (anal fissures), hemorrhoids, and weight loss.