Background

• The leaves or pods of the senna plant (Cassia senna) have been used by Arab physicians for their laxative properties since at least the ninth Century. Today, senna is a U.S. Food and Drug Administration (FDA)-approved nonprescription drug and an ingredient in several commercial laxatives.
• There are over 400 known species of Cassia. Both the leaves and the seedpods (fruit) have laxative activity, due to the presence of compounds called anthraquinones. These compounds found in senna are also found in other plants with laxative properties, including cascara (Cascara sagrada), rhubarb (Rheum spp.), and aloe (Aloe vera). Senna accelerates defecation, in contrast to softening the stools, as some laxatives do. When taken at much higher than recommended doses or when used for the long term (laxative abuse), adverse effects, such as low blood potassium, may occur.
• Some evidence supports the use of senna in adults for the treatment of chronic constipation or constipation induced by childbirth or drugs. In children, the available evidence suggests that mineral oil and lactulose may be safer and more effective than senna for treating chronic constipation. Some experts believe that senna is a more acceptable laxative than cascara or aloe for drug-induced constipation. Approximately 80% of terminal cancer patients who are taking opioids for pain relief require laxatives. Some evidence suggests that senna may be as effective and safe as lactulose for these patients.

References

1. Fingerhut A, Hay JM. Single-dose ceftriaxone, ornidazole, and povidone-iodine enema in elective left colectomy. A randomized multicenter controlled trial. The French Association for Surgical Research Arch Surg 1993;128(2):228-232. View Abstract
2. Fournier AM. [Use of senna for the acceleration of small intestine transit in hospital radiology]. Mars Med 1971;108(6):469-474. View Abstract
3. Glatzel, H. [Senna--an old drug in a new form]. Z Allgemeinmed 1970;46(2):82-84. View Abstract
4. Godding EW. Laxatives and the special role of senna. Pharmacology 1988;36 Suppl 1:230-236. View Abstract
5. Han RX. [Study of the cleansing effect of senna on the intestinal tract]. Zhonghua Hu Li Za Zhi 1989;24(5):273-275. View Abstract
6. Heaton KW, Cripps HA. Straining at stool and laxative taking in an English population. Dig Dis Sci 1993;38(6):1004-1008. View Abstract
7. Langmead L, Rampton DS. Review article: herbal treatment in gastrointestinal and liver disease--benefits and dangers. Aliment Pharmacol Ther 2001;15(9):1239-1252. View Abstract
8. Mishalany H. Seven years' experience with idiopathic unremitting chronic constipation. J Pediatr Surg 1989;24(4):360-362. View Abstract
9. Monias MB. Standardized senna concentrate in postpartum bowel rehabilitation. Md State Med J 1966;15(2):32-33. View Abstract
10. No authors listed. Senna and habituation. Pharmacology 1992;44 Suppl 1:30-32. View Abstract
11. Pahor M, Mugelli A, Guralnik JM, et al. Age and laxative use in hospitalized patients. A report of the "Gruppo Italiano di Farmacovigilanza nell'Anziano--GIFA". Aging (Milano) 1995;7(2):128-135. View Abstract
12. Senna in the puerperium. Pharmacology 1992;44 Suppl 1:23-25. View Abstract
13. Tooson JD, Gates LK, Jr. Bowel preparation before colonoscopy. Choosing the best lavage regimen. Postgrad Med 1996;100(2):203-12, 214. View Abstract
14. Vaidyanathan S, Soni BM. Bluish discolouration of urine drainage tube and bag in a female patient with spina bifida, paraplegia, and suprapubic cystostomy. ScientificWorldJournal 2007;7:1070-1072. View Abstract
15. Valverde A, Msika S, Kianmanesh R, et al. Povidone-iodine vs sodium hypochlorite enema for mechanical preparation before elective open colonic or rectal resection with primary anastomosis: a multicenter randomized controlled trial. Arch Surg 2006;141(12):1168-1174. View Abstract