Last reviewed 2026-04-22 · How we verify

Senna tablets

Senna stimulates colonic muscle contractions and increases intestinal fluid secretion to promote bowel movements.

Senna stimulates colonic muscle contractions and increases intestinal fluid secretion to promote bowel movements. Used for Constipation, Bowel evacuation before diagnostic procedures.

At a glance

Mechanism of action

Senna contains anthraquinone glycosides (sennosides) that are metabolized by colonic bacteria into active aglycones. These compounds irritate the colonic mucosa and stimulate peristalsis while also increasing water and electrolyte secretion into the intestinal lumen, resulting in a laxative effect that typically occurs 6-12 hours after ingestion.

Approved indications

• Constipation
• Bowel evacuation before diagnostic procedures

Common side effects

• Abdominal cramping
• Diarrhea
• Nausea
• Electrolyte imbalance (with chronic use)

Key clinical trials

• Optimization of Postoperative Bowel Habits (NA)
• Whatsapp Based Patient Education to Improve Bowel Preparation for Colonoscopy (NA)
• PEG3350 vs Senna After Urogyn Surgery (PHASE4)
• ACL-R Opioid Sparing Study (PHASE3)
• Mechanical Bowel Preparation and Oral Antibiotics Before Rectal Cancer Surgery (PHASE3)
• Naloxegol to Prevent Lower Gastrointestinal Paralysis in Critically Ill Adults Administered Opioids (PHASE4)
• Mechanical Bowel Preparation and Oral Antibiotics Before Colon Cancer Surgery (PHASE3)
• A Double-blinded,Double-dummy Clinical Trial of Chinese Herbal Medicine (MaZiRenWan) for Functional Constipation (PHASE2)

Primary sources

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