Laxatives: OTC Products for Constipation

Over-the-counter (OTC) products are medicines you can buy without a doctor’s prescription. Many products are advertised to relieve constipation, including bulk-forming laxatives, lubricants, stool softeners, saline laxatives, stimulant laxatives and combinations. Download the PDF file below for examples of these types of laxatives.

Bulk-forming laxatives add bulk and water to your stools. The larger stools help trigger the bowel to contract and move the stools out. You must use bulk-forming laxatives daily for them to work. Start slowly and drink plenty of fluids. Gradually increase how much you use to reduce the chance of having any side effects.

Lubricant laxatives work by coating the surface of the stools. This helps the stools hold in water so they move out of the body more easily. Glycerin suppositories lubricate the inside of the anus (the outside opening to the intestine) to make it easier to pass hard stools.

Stool softeners help mix fluid into stools to soften them. This makes stools easier to pass out of the body.

Saline laxatives draw fluid into the bowel from nearby tissue. This softens stools and helps the bowel move them out.

Stimulant laxatives are the harshest laxatives. They cause the bowel to squeeze or contract to move the stools out. Stimulant laxatives should generally be used only when your doctor recommends them, such as if you’re preparing for a bowel exam or if you’ve just had surgery and shouldn’t strain to have a bowel movement.

Most of the time, constipation doesn’t require treatment with laxatives. It will go away on its own or if you make changes in your diet and other habits. For example, you can treat constipation by eating enough fiber, drinking enough fluids and getting enough exercise. See Constipation: Keeping Your Bowels Moving Smoothly for more information.

Laxatives aren’t meant for long-term use. Don’t use laxatives for longer than 1 week unless you’re following your doctor’s advice. Long-term use or overuse of laxatives can cause health problems. Also, using laxatives too much may hide symptoms that would be important for your doctor to know about. This could delay finding out about problems you have and delay the treatment you need.

One exception is bulk-forming laxatives. They can be used on a daily basis to help ease symptoms of irritable bowel syndrome, hemorrhoids and other bowel problems.

Most laxatives don’t have side effects if you use them correctly. Sometimes they can cause cramping, gas, bloating, nausea or diarrhea.

Stimulant laxatives are most likely to cause side effects. These can include abdominal discomfort, faintness and cramps.

With bulk-forming laxatives, you may notice some bloating, gas or cramping at first. This is more likely if you take too much or increase the amount you’re using too quickly. These symptoms should go away in a few weeks or less.

If mineral oil is accidentally aspirated (breathed into the lungs), it can cause a type of pneumonia. Older adults or anyone who might have trouble swallowing generally shouldn’t use this type of laxative.

Don’t take laxatives if you have an allergy to any of the ingredients. Some people may be allergic to psyllium, a key ingredient in one type of bulk-forming laxative.

Phenylalanine is another example of an ingredient that can cause a problem for certain people. If you have a condition called phenylketonuria, you shouldn’t take a laxative that contains phenylalanine.

Other ingredient-related warnings concern your diet while you’re taking a laxative. Unless your doctor tells you it’s OK, don’t use products that contain sodium bicarbonate and potassium bitartrate if you’re on a low-salt diet. Don’t take magnesium hydroxide if you’re following a magnesium-restricted diet.

Look on the label in the “Active Ingredient” and “Inactive Ingredient” sections to find out what ingredients each product contains. If you have any questions, talk to your family doctor or pharmacist.

Yes. Laxatives can get in the way of how your body absorbs certain medicines and some nutrients.

In general, don’t take any other medicines within 2 hours of taking a laxative. If you’re taking a prescription medicine of any kind, talk to your doctor before taking a laxative. You also shouldn’t mix different types of laxatives.

Don’t take bisacodyl within 1 hour of taking antacids or drinking milk.

While mineral oil and castor oil may have their place as laxatives, they shouldn’t be used often. If mineral oil is used often, it can cause deficiencies of vitamins A, D, E and K. Castor oil can also lead to serious problems if it’s used regularly.

If you have any of the following symptoms, talk to your doctor before using a laxative:

Stop taking laxatives and call your doctor if you have any bleeding from your rectum (the last part of the large intestine) or if you don’t have a bowel movement after using a laxative. These could be signs of a more serious problem.

You may have to retrain your body to go without laxatives if you’ve been using them for a long time. This means eating plenty of fiber and using a bulk-forming laxative, drinking lots of water, exercising and giving yourself time to have a bowel movement.

If you’ve used laxatives for a long time, your family doctor may suggest that you wean yourself off of them slowly to give your system a chance to return to normal. Be patient—it may take many months for your bowels to get back to normal if you've been using laxatives regularly. Talk with your family doctor about any concerns you have.

When choosing an OTC medicine to treat constipation, check the drug label for possible side effects or interactions with other drugs you’re taking. This information will appear in the “Warnings” section of the label.

Be sure to check that you’re not taking two medicines that contain the same ingredient. You’ll find this information in the “Active Ingredient” section. Also check the label to make sure the product doesn’t contain anything that you might be allergic to.

Always read and follow the directions on the label. Be sure you understand what the label says before taking the medicine. If you have any questions, ask your family doctor or pharmacist.