Laxatives

Topic Overview

What is a laxative?

A laxative is a substance that helps you have a bowel movement. Laxatives are used to relieve and prevent constipation, which occurs when it is difficult to have a bowel movement.

What types of laxatives are there?

There are four types of products for preventing or treating constipation.

• Bulking agents. Food such as bran or products such as Citrucel, Metamucil, Fibercon, or Perdiem ease constipation by absorbing more fluid in the intestines. This makes the stool bigger, which gives you the urge to pass the stool. Regular use of bulking agents is safe and often lets you have more stools.
• Stool softeners. Products such as Colace lubricate and soften the stool in the intestine, making it easier to pass. Stool softeners do not usually cause problems but are less likely to be effective if you do not drink enough water during the day.
• Osmotic laxatives. Products such as Fleet Phospho-Soda or Milk of Magnesia and non-absorbable sugars, such as lactulose or sorbitol, keep fluids in the intestine and also draw fluids into the intestine from surrounding tissue and blood vessels. The increased fluid in the intestines makes the stool softer and easier to pass. You should drink plenty of water when using this type of laxative. If you have high blood pressure, kidney disease, or heart failure, or are on a sodium-restricted diet, you should not use osmotic laxatives.
• Stimulant laxatives. Products such as Correctol, Dulcolax, Ex-Lax, or Senokot speed up the passage of stool by irritating the lining of the intestines. Regular use of stimulant laxatives is not recommended. Overuse of stimulant laxatives decreases tone and sensation in the large intestine and may cause you to become laxative-dependent—you have to use the laxative all the time in order to have a bowel movement, not just when you are constipated.

Are there precautions for taking laxatives?

• Take any laxative or bulking agent with plenty of water or other liquids.
• Do not take stimulant laxatives regularly. Overuse of stimulant laxatives decreases tone and sensation in the large intestine and may cause laxative dependence. If you need help staying regular, use a bulking agent, such as bran or psyllium (for example, Metamucil).
• Do not use osmotic laxatives if you have high blood pressure or kidney disease or are on a sodium-restricted diet.
• Regular use of stimulant laxatives—such as Correctol, Dulcolax, Ex-Lax, or Senokot—may interfere with your body's absorption of vitamin D and calcium. This can cause weakening of your bones (osteopenia).

Are there other ways to treat constipation?

There are many other ways to treat constipation, such as drinking more water or adding more fibre, fruits, and vegetables to your diet. These are often recommended in addition to taking laxatives.

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Author:	Jan Nissl, RN, BS	Last Updated: February 2, 2007
Medical Review:	William M. Green, MD - Emergency Medicine Anne C. Poinier, MD - Internal Medicine Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology
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