Senna is categorized as which laxative type?

• A. Osmotic laxative
• B. Stimulant laxative
• C. Bulk-forming laxative
• D. Lubricant laxative

Answer: (B)

The statement tests how laxatives are classified by how they work. Senna acts as a stimulant laxative, meaning its effect comes from directly irritating the intestinal lining to provoke increased peristaltic contractions. This speeds stool movement through the colon.

This differs from other laxatives: osmotic laxatives pull water into the bowel to soften stool, bulk-forming laxatives add fiber to increase stool bulk, and lubricant laxatives coat stool to ease passage. With Senna, the primary action is stimulation of the intestinal nerves to boost motility, which is why it’s categorized as a stimulant laxative. Onset of action for oral senna is typically within about 6–12 hours. In older adults, monitor for cramping and electrolyte disturbances with use.