Learn how over-the-counter laxatives relieve constipation and which are safe to use.
If you've ever experienced the discomfort of constipation — perhaps while traveling or after a change in your diet — you may have considered over-the-counter laxatives. Laxatives are substances taken by mouth (oral laxatives) or in your rectum (an enema or suppositories) that relieve and prevent constipation. You can take oral laxatives in many different forms — liquids, tablets, wafers, gums, or powders that you dissolve in water. You take rectal laxatives in the form of suppositories or enemas.
How often you have a bowel movement varies, but a "normal" frequency ranges from as many as three a day to as few as two a week. Your body ordinarily needs no help to have them. But a poor diet, physical inactivity, pregnancy, illness or some medications can disrupt normal bowel function and cause constipation. Before turning to laxatives for relief, you may want to try the following lifestyle changes to help manage occasional irregularity:
- Eat fiber-rich foods.
- Drink plenty of fluids daily.
- Get regular exercise.
How laxatives relieve constipation
Laxatives work in different ways, and the effectiveness of each laxative type varies from person to person. In general, bulk-forming laxatives, such as Metamucil and Citrucel are the gentlest on your body and safe to use long term, whereas stimulant laxatives, such as Ex-lax and Senokot, are the harshest and shouldn't be used long term. If you remain constipated despite changing your diet and exercise routine, your next choice may be a mild laxative.
Following are some examples of common types of laxatives. Other types of laxatives also exist. Talk to your doctor about what laxative may be right for you.
Type of laxative
(brand examples) | How they work | Side effects |
| Oral hyperosmotics (Epsom salts, Phillips' Milk of Magnesia) | Draw water into colon from surrounding body tissues to allow easier passage of stool | Bloating, cramping, diarrhea, nausea, gas, increased thirst |
| Oral bulk formers (Citrucel, Metamucil) | Absorb water to form soft, bulky stool, prompting normal contraction of intestinal muscles | Bloating, gas, cramping, choking or increased constipation if not taken with enough water |
| Oral stool softeners (Colace, Surfak) | Add moisture to stool to allow strain-free bowel movements | Throat irritation, stomach or intestinal cramping |
| Oral stimulants (Ex-lax, Senokot) | Trigger rhythmic contractions of intestinal muscles to eliminate stool | Belching, cramping, diarrhea, nausea, faintness, urine discoloration |
| Rectal stimulants (Fleet Bisacodyl, Dulcolax) | Trigger rhythmic contractions of intestinal muscles to eliminate stool | Rectal irritation, stomach discomfort, faintness, cramping |
In addition, oral laxatives such as those listed above may interfere with your body's absorption of some medications and food nutrients. Rectal laxatives do not have this effect.
Don't be lax about laxatives
See your doctor if you have unexplained changes in bowel patterns or habits, if constipation lasts longer than seven days despite laxative use, or if constipation is accompanied by rectal bleeding. If you're dependent on laxatives, ask your doctor for advice on how to gradually withdraw from them and restore your colon's natural ability to contract.
Last Updated: 04/27/2007
