Osmotic laxatives are described as indigestible and hydrophilic colloids that absorb water, forming a bulky, emollient gel that distends the colon and promotes peristalsis.

• A. True
• B. False
• C. Not described
• D. Not relevant

Answer: (A)

Osmotic laxatives work by staying in the gut as indigestible, hydrophilic substances that draw water into the intestinal lumen. This increases stool water content and volume, softening the stool and creating a bulky mass. That bulk distends the colon walls, activating stretch receptors and promoting peristalsis to move the stool along. The description of forming a bulky, emollient gel reflects the result of water retention in the stool and the subsequent mechanical stimulus to the colon, which is exactly how these agents help relieve constipation.