Which natural stimulant laxative is used for chronic constipation?

• A. Psyllium
• B. Senna
• C. Docusate
• D. Bisacodyl

Answer: (B)

Identifying laxatives by their action helps you see why this choice fits for chronic constipation. A natural stimulant laxative works by actively triggering the nerves in the colon to increase peristalsis, speeding up bowel movements. Senna does exactly that: its active compounds (sennosides) irritate the colonic mucosa and stimulate the smooth muscle of the colon, leading to a bowel movement. That stimulant effect makes it effective for constipation that persists over time, including chronic cases, when used appropriately. Onset is typically several hours after ingestion, though it can vary with formulation.

Because it stimulates the gut, long-term use should be monitored to avoid issues like dependence, electrolyte imbalances, and, with prolonged use, changes in the colon lining known as melanosis coli. For chronic constipation, it’s common to rotate approaches or emphasize non-stimulant strategies (like dietary fiber and fluids) while using stimulant laxatives only as needed or for short-term relief. The other options don’t fit as natural stimulant laxatives: one is a bulk-forming fiber that adds stool bulk without stimulating nerves; another is a stool-softening agent that eases passage but doesn’t provoke movement; and the last is a stimulant laxative, but it’s synthetic rather than natural.