Laxatives

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Laxatives

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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 Metamucil, Fibercon, or Prodiem 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 often cause problems but do not work as well if you do not drink enough water during the day.
  • Osmotic laxatives. Products such as Fleet Phospho-Soda, Milk of Magnesia, or Miralax and non-absorbable sugars such as lactulose or sorbitol hold fluids in the intestine and draw fluids into the intestine from other tissue and blood vessels. This extra fluid in the intestines makes the stool softer and easier to pass. Drink plenty of water when you use this type of laxative. If you have high blood pressure (hypertension), kidney disease, 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 how fast a stool moves through the intestines by irritating the lining of the intestines. Regular use of stimulant laxatives is not recommended. Stimulant laxatives change the tone and feeling in the large intestine and you can become dependent on using laxatives all the time to have a bowel movement.

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. Stimulant laxatives change the tone and feeling in the large intestine and you can become dependent on using laxatives all the time to have a bowel movement. If you need help having regular bowel movements, use a bulking agent, such as bran or psyllium (for example, Metamucil).
  • Do not use osmotic laxatives if you have high blood pressure, heart failure, or kidney disease or are on a sodium-restricted diet.
  • Regular use of stimulant laxatives—such as Correctol, Dulcolax, Ex-Lax, or Senokot—may change your body's ability to absorb 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.

Credits

By Healthwise Staff
Primary Medical Reviewer William H. Blahd, Jr., MD, FACEP - Emergency Medicine
Specialist Medical Reviewer David Messenger, MD
Last Revised December 8, 2010

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.