Sickle Senna (Senna alexandrina or Senna angustifolia), commonly known simply as "senna," has a long history of use as a natural laxative to support bowel movements. Its primary active compounds are sennosides, which are anthraquinone glycosides. These compounds are scientifically validated as stimulant laxatives: they work by irritating the lining of the colon, promoting peristalsis, and facilitating defecation. This action directly supports the rectum and lower gastrointestinal tract by encouraging the passage of stool, making Senna an effective short-term remedy for constipation.

Numerous clinical trials and systematic reviews have confirmed the efficacy of Senna in relieving constipation, including in populations such as the elderly, post-operative patients, and individuals on opioid medications. For example, a Cochrane review (2011) concluded that Senna preparations are effective in the management of constipation in adults. The FDA recognizes Senna as an over-the-counter laxative.

However, its use should be limited to short-term or occasional relief. Chronic or overuse of Senna may lead to electrolyte imbalance, dependence, and potential harm to the colonic mucosa. Despite this, the scientific evidence for Senna's use to support rectal evacuation and relieve constipation is robust, justifying its widespread use in both clinical and non-clinical settings.