Laxatives

Types

Bulk-forming agents

Substances, such as dietary fiber and hydrophilic agents that add bulk and water to more easily through the intestines.

• Site of action: Small and large intestines
• Onset of action: 12–72 hours
• Examples: dietary fiber, psyllium (Metamucil), methylcellulose (Citrucel), polycarbophil (FiberCon)

Dietary fiber

Includes insoluble fiber and soluble fiber, such as:

• Fruits, such as bananas, kiwifruits, prunes, apples (with skin), pears (with skin), and raspberries
• Vegetables, such as broccoli, string beans, kale, spinach, cooked winter squash, cooked green peas, and baked potatoes (with skin)
• Whole grains
• Bran products
• Nuts
• Legumes, such as beans, peas, and lentils

Emollient agents (stool softeners)

Anionic surfactants that enable additional water and fats to be incorporated in the stool, making it easier for them to move through the gastrointestinal tract.

• Site of action: small and large intestines
• Onset of action: 12–72 hours
• Examples: docusate (Colace, Diocto), Gibs-Eze

Lubricant agents

Coat the stool with slippery lipids and retard colonic absorption of water so that the stool slides through the colon more easily. Lubricant laxatives also increase the weight of stool and decrease intestinal transit time.

• Site of action: colon
• Onset of action: 6–8 hours
• Example: mineral oil