Senna leaf is derived from the small leaves of the leguminous plant senna narrow leaf or senna pointed leaf. The active ingredient in senna leaves is called sennoside. This constituent molecule is converted by microorganisms in the colon into another substance, anthrone rhubarate, which has the beneficial effects of stimulating colon activity (it accelerates intestinal motility and improves digestion) and increasing fluid secretion. The purgative action of sennoside and its active metabolite anthrone rhehubarate are thought to inhibit the absorption of water and electrolyte by the large intestine, thereby increasing the volume and pressure of intestinal contents. It stimulates the propulsive constriction of the colon. In addition, the stimulating effect on the secretion of active chloride increases the contents of intestinal water and electrolyte. These changes in the transport of the active electrolyte depend on the calcium element on the serous membrane surface. The laxative effect of sennoside is partly mediated by the stimulation of colonic fluid and electrolyte secretion, and this secretion capacity is regulated by the stimulation of endogenous prostaglandin formation. Sennoside can be prepared as an enema or suppository or mixed with a stool softener or a lumped fiber laxative to form a combined purgative.