Laxative
Laxatives (purgatives, aperients) are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation. Laxatives vary based on how they work and the side effects they have. Certain stimulant, lubricant and saline laxatives are used to evacuate the colon for rectal and bowel examinations, and may be supplemented by enemas under certain circumstances. Sufficiently high doses of laxatives may cause diarrhea.
Some laxatives combine more than one active ingredient. Laxatives may be oral or suppository in form.
Uses
Acute and chronic constipation
Bowel preparation
Chronic immobility
Types
Bulk-forming agents
Bulk-forming laxatives, also known as roughage, are substances, such as fiber in food and hydrophilic agents in over-the-counter drugs, that add bulk and water to stools so that they can pass more easily through the intestines (lower part of the digestive tract).
Properties
Site of action: small and large intestines
Onset of action: 12–72 hours
Examples: dietary fiber, Metamucil, Citrucel, FiberCon
