How Stool Softeners Work and Differ From Other Laxatives

Stool softeners, also known as emollient laxatives, are over-the-counter (OTC) medications used to soften hard stools. While other types of laxatives stimulate the digestive tract or draw water into the intestine to encourage a bowel movement, stool softeners work by increasing moisture in stools so they are easier to pass.

Stool softeners are taken by mouth and come in capsule, liquid, and tablet form. Brand names include Colace, Correctol, Diocto, Doxinate, Ex-Lax Stool Softener, Fleet Sof-Lax, Modane Soft, Phillips' Stool Softener, and Surfak.

This article explains how stool softeners work, when and how to take them, and what side effects are possible.

How Stool Softeners Work

Stool softeners are made of compounds called surfactants that change the consistency of stools so that more moisture can be drawn in. When this happens, stools become softer, meaning you don't have to strain to pass them.

Docusate sodium is the active ingredient used in OTC stool softeners. Unlike many other types of laxatives, but similar to fiber supplements, docusate sodium draws water into the stool rather than to the interior of the intestine.

Stool softeners don't work immediately. It may take up to 72 hours before they induce a bowel movement.

When They Are Used

Excessive and recurrent straining to have a bowel movement is uncomfortable and can cause blood vessels around the anus to swell, blood pressure to increase, and tissues to be disrupted. For some people, this can cause serious harm.

For most people with constipation, healthcare providers recommend eating a high fiber diet along with drinking plenty of water or other liquids, as well as exercising regularly. Stool softeners can be a reasonable option when these strategies don't work.

Situations when stools softeners may be recommended:

• When dealing with hemorrhoids
• When recovering from an anal fissure
• Following childbirth
• Following surgery
• Following a heart attack
• If you have certain heart conditions
  

Stool Softener or Another Laxative?

Stool softeners are intended for short-term use. They can treat occasional constipation, but other laxatives may be better suited for the task, as they typically work faster.

For instance, if you have not had a bowel movement for several days and are cramping, the following laxatives may be used instead:

• Stimulant laxatives like Ex-Lax and Ducalax, increase intestinal contractions but may increase intestinal cramping.
• Hyperosmotic laxatives like Miralax, increase water in the intestines so stools can exit more rapidly.
• Saline laxatives like Phillips' Milk of Magnesia use sodium to draw water into the intestines to help stools get through more easily.

Healthcare providers rarely recommend saline laxatives because there are safer and more effective alternatives. If you have heart disease or kidney disease, you should talk with your healthcare provider before taking Milk of Magnesia.

Bulk-forming laxatives like psyllium found in Metamucil and methylcellulose found in Citrucel may be the gentlest and safest options for longer-term treatment of chronic constipation.

How to Use

A stool softener is usually taken before you go to bed at night. Be sure to follow the package instructions and never exceed the recommended dose.

If you choose a softener in capsule or tablet form, take it with a full 8-ounce glass of water. Drink plenty of water throughout the day to help induce bowel movements.

Liquid stool softeners often come with a pre-marked dosing cap; if not, measure each dose with a measuring spoon (not a dinner spoon).

It's best that you have a bathroom nearby.

Stool softeners are generally not used for longer than one week.

Side Effects and Risks

Stool softeners are not absorbed into the bloodstream and are generally well-tolerated. Side effects are rare.

Some users report mild side effects such as:

• Nausea
• Stomach cramps
• Bloating
• Throat irritation (with liquid stool softeners)

If your constipation is chronic, it is better to use a bulk-forming laxative that you can take once daily.

Stool softeners may be safe for children or people who are pregnant, but speak with a doctor first before using any OTC product to treat constipation.

Summary

Stool softeners are used to soften stools and prevent bowel straining. They work by adding moisture to stools, making them easier to pass. This is especially important when straining poses health risks, for example, if you have hemorrhoids or certain heart problems.

Stool softeners can take up to 72 hours to work and are intended for short-term use. For the rapid relief of constipation, other laxatives may a better choice.