Stool Softeners vs. Laxatives

Medically reviewed by Aleah Rodriguez, PharmD on August 29, 2016Written by University of Illinois-Chicago, Drug Information Group

Introduction

Constipation can be extremely uncomfortable, and it can affect anyone due to many different causes. There are also many types of over-the-counter laxatives, so choosing the right one may seem a little tricky. How does each type work? How is each used? What’s the difference between a stool softener and a laxative? Let us help you sort some of this out.

Stool softeners and laxatives

First of all, let’s sort out the difference between stool softeners and laxatives. A laxative is a substance that you use to help you have a bowel movement. A stool softener is a type of laxative, called an emollient laxative. So, all stool softeners are laxatives, but not all laxatives are stool softeners.

In fact, there are many types of laxatives. Because many different things can cause constipation, laxatives work in different ways to resolve your constipation. Some work on your stool, some work on your intestine, and others work on both your stool and intestine. All laxatives are used to relieve constipation. Some may be a better choice for you than others, though, especially depending on how long you need to use them and how harsh the ingredients can be on your body.

Emollient laxative (also known as a stool softener)

Active ingredients: docusate sodium and docusate calcium

How it works: It helps wet and soften the stool.

Considerations for use: Stool softeners are gentle enough to prevent constipation with regular use. However, they’re the least effective option for treating constipation. They’re best for people with temporary constipation or mild, chronic constipation.

Bulk-forming laxative

Active ingredients: psyllium, methylcellulose, and calcium polycarbophil

How it works: It forms a gel in your stool that helps hold more water in your stool. The stool becomes bigger, which stimulates movement in your intestine to help pass the stool more quickly.

Considerations for use: Bulk-forming laxatives can be used for longer periods and with little risk of side effects. They’re a good option for people with chronic constipation. However, they take longer than other laxatives to work. You shouldn’t use them continuously for longer than one week without talking to your doctor.

Lubricant laxative

Active ingredient: mineral oil

How it works: It coats your stool and intestines to prevent water loss. It also lubricates your stool to help it move more easily.

Considerations for use: Mineral oil is not for use on a regular basis. It can interfere with your body’s absorption of fat-soluble vitamins, such as vitamins A, D, E, and K. Lubricant laxatives are typically only good options for immediate relief of short-term constipation.

Hyperosmotic laxative

Active ingredients: polyethylene glycol and glycerin

How it works: It draws more water into your intestines. This helps soften the stool to help it move more easily.

Considerations for use: Hyperosmotic laxatives can also be used for longer periods with little risk of side effects. Like bulk-forming laxatives, they’re a good option for people with chronic constipation and they take longer than other laxatives to work. You shouldn’t use them continuously for longer than one week without talking to your doctor.

Saline laxative

Active ingredients: magnesium citrate and magnesium hydroxide

How it works: It draws more water into the intestine. This softens the stool and stimulates movement in your intestines to help you pass it.

Considerations for use: Saline laxatives should not be used on a regular basis. When used regularly, they can cause dehydration and electrolyte imbalances.

Stimulant laxative

Active ingredients: bisacodyl and sennosides

How it works: It stimulates and increases the movement of your intestines.

Considerations for use: Stimulant laxatives also should not be used on a regular basis. When used regularly, they can cause dehydration and electrolyte imbalances.

Forms

Laxatives come in many different forms. Some are used by mouth and some are used in your rectum.

Stool softeners are available as:

Other laxatives come in these forms:

  • oral capsule
  • chewable tablet
  • oral tablet
  • oral granules (powder)
  • oral gummy
  • oral liquid
  • oral wafer
  • rectal suppository
  • rectal enema

Timing

Emollient, bulk-forming, hyperosmotic, and saline (magnesium hydroxide) laxatives typically take 12 to 72 hours to work. Stimulant laxatives take six to 12 hours. Saline (magnesium citrate solution) laxatives work a little more quickly, taking 30 minutes to six hours.

Regardless of which type of laxative you use, rectal enemas and suppositories usually work the fastest. They usually take two to 15 minutes, but in some cases have taken up to an hour to work.

Dosage

Dosages for laxatives vary, even among laxatives of the same type. You shouldn’t need to use a laxative for longer than a week, though. If your bowel movements still aren’t regular after using a laxative for seven days, contact your doctor before you use it any longer.

Generally, laxatives are safe for people who are 12 years or older. Some products provide dosages for children who are younger than 12 years, but you should talk to your doctor before giving any laxative to a child.

Side effects and interactions

Side effects

Most people can use laxatives without any side effects, but some side effects are possible. The following table lists some of the milder as well as the more serious side effects of stool softeners and other laxatives. The more serious side effects are usually much less common. If you do have serious side effects, contact your doctor immediately.

Milder side effectsStool softenersAll other laxatives
stomach crampsXX
nausea XX
throat irritation (with oral liquid)X
bloating and gas X
faintness X
Serious side effectsStool softenersAll other laxatives
allergic reaction *XX
vomiting XX
rectal bleeding X
severe diarrhea X
*may cause hives and difficulty breathing or swallowing

Interactions

Laxatives can also interact with other drugs, vitamins, and supplements that you take. If you take any medication, it’s important to talk with your doctor to make sure it’s also safe to take a laxative. Your doctor may even recommend a specific laxative, depending on the medication you take. For example, mineral oil can interact with stool softeners.

Examples of drugs that can interact with other laxatives include:

Laxative misuse

You may have heard that you can use laxatives to lose weight. However, there are no studies that support the use of laxatives for weight loss. Further, using higher doses of laxatives for long periods can result in a much higher risk of the following effects, some of which can be severe:

Pharmacist’s advice

With any laxative, there are things you can do to help them work their best. The following tips can help you work with your laxative to relieve constipation and keep you regular.

  • Drink 8-10 cups of water per day.
  • Try not to skip meals.
  • Eat more fruits and vegetables to increase the fiber in your diet.
  • Exercise to help keep all of your body systems active.
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