Senna leaf possesses very powerful medicinal properties.
Senna is used in modern medicine as a laxative; acting on the lower bowel, it is especially useful in alleviating constipation.
Senna encourages bowel movement by inhibiting the smooth muscles that retain stool and stimulating the smooth muscles that push stool through the intestine.
The stimulant action of sennosides should be taken into account for those who suffer from any conditions where stimulants are contraindicated, such as past heart disease, high blood pressure, anxiety attacks, etc. A (generally invisible and harmless) side effect of taking Senna medication regularly is Melanosis coli, a brown discoloration of the colon wall.