<p>Senna glycoside, also known as sennoside or senna, is a medication used to treat constipation and empty the large intestine before surgery. The medication is taken by mouth or via the rectum. It typically begins working in minutes when given by rectum and within twelve hours when given by mouth. It is a weaker laxative than bisacodyl or castor oil.<br />
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Sennosides A and B increase intestinal motility through release of active anthraquinones into the colon by colonic bacteria. Purified sennosides (sennosides A and B) are used similarly to senna.</p>