Laxatives are products that help people to poop by causing bowel movements. Stool softeners are a type of laxative that works by drawing water into the stool, making it softer and more comfortable to pass.
All laxatives work in different ways, each with the intention of helping to relieve constipation. Understanding the differences between laxatives and stool softeners may help a person decide which one to use.
Anyone dealing with regular constipation may also choose to make a few changes to their diet and lifestyle, which might help regulate their bowel movements.
What are stool softeners and laxatives?
People should only take one type of laxative at a time.
The term laxative refers to a wide range of substances, including stool softeners.
A laxative is any medicine or supplement that helps the body have a bowel movement. Each laxative works differently.
Stool softeners are a type of laxative that works to gently lubricate the stool by adding a compound to it that absorbs water. They are also called emollient laxatives.
There are many types of laxatives because there are many different causes of constipation. Doctors may recommend different types of laxative depending on the cause of constipation or side effects of the medications.
Stool softeners are a type of laxative, but not all laxatives are stool softeners. Although some other laxatives also soften the stool, they have different methods of action.
Other types of laxatives include:
- Osmotic laxatives. These laxatives draw water into the intestines from the surrounding tissues.
- Bulk-forming laxatives. Often derived from plants, these laxatives help form a watery gel in the intestines that adds both body and lubrication to the stool.
- Stimulant laxatives. Fast acting laxatives that can stimulate the intestines into having a bowel movement.
- Saline laxatives. Magnesium-based laxatives that pull water into the intestines.
- Lubricant laxatives. Oily laxatives that coat the intestines to help move stool through quicker.
- Guanylate cyclase-C agonist laxatives. Certain drugs both increase water in the gastrointestinal tract and make the stool move through the colon faster.
Only take one type of laxative at a time, and talk to a doctor before switching between them to avoid any interactions or complications.
We discuss these types of laxatives in more detail below.
Which constipation relief method is best for me?
In most cases, a doctor will know which type of laxative they should prescribe based on the person's symptoms and what is causing them.
The following list will describe the uses, benefits, and risks of different forms of laxatives:
A doctor will prescribe a laxative based on the person's symptoms.
Stool softeners are gentle medications with a relatively mild effect. They soften the stool, making it easier to pass.
Over-the-counter stool softeners are useful when a person experiences mild occasional or chronic constipation.
Doctors may prescribe stool softeners after major surgeries, such as heart surgery or hernia repair. If straining to have a bowel movement might be harmful during recovery, people can take stool softeners to avoid complications.
Osmotic laxatives work by drawing water into the intestines. They may not be the best option for people experiencing constipation from dehydration.
Anyone using osmotic laxatives should also drink more water throughout the day. When used correctly, doctors may recommend osmotic laxatives for long-term use.
Doctors may recommend a bulk-forming laxative containing soluble fiber if a person does not get a lot of fiber in their regular diet. Doctors may also recommend fiber-based laxatives for people who have chronic, long-lasting constipation.
Bulk-forming laxatives may be safer for long-term use than other options, as they have little risk of long-term side effects when taken correctly.
Like osmotic laxatives, saline laxatives pull water into the stool. Saline laxatives do this using mineral salts, such as magnesium citrate or magnesium oxide.
Saline laxatives are not right for everyone. For instance, people who are on medication to lower their sodium levels or are taking other mineral-based medications, such as medicines to reduce calcium in the kidneys, should avoid saline laxatives.
Saline laxatives are useful for short-term constipation. Using them for extended periods may lead to dehydration or cause an imbalance in other minerals.
Doctors may recommend laxatives containing oils, such as mineral oil for difficult short-term constipation, but they are not suitable for regular use. The oils in these laxatives may stick to fat-soluble vitamins and make them impossible to digest.
Stimulant laxatives are a good option for fast relief from painful constipation.
The stimulating effect in these laxatives makes the stool move faster through the colon while increasing the liquid in the stool. Many popular over-the-counter brand names contain stimulant laxatives.
Stimulant laxatives are not safe for regular use. Using them regularly may cause the body to become dependent on the laxative to have a bowel movement.
Guanylate cyclase-C agonist laxatives
Doctors may prescribe guanylate cyclase-C agonist laxatives in cases of chronic constipation that has no known cause. These laxatives, along with lifestyle changes, may offer a solution for people who suffer from chronic constipation. Young children should not use them.
Which laxatives work fastest?
Stool softeners may be best when a person does not need immediate relief but is looking to regulate their bowel movements within the next few days.
The type of laxative the doctor recommends may also change based on how quickly the person needs relief. Individual result times may vary, but in general:
- Quick-relief – saline laxatives tend to work very fast.
- Medium-relief – stimulant laxatives are fast-acting, but still take some time to work.
- Slow-relief – other laxatives, including bulk-forming fibers, stool softeners, and guanylate cyclase-C agonist laxatives, take longer to work.
According to a 2015 study looking at constipation in older adults:
- Osmotic laxatives, including magnesium citrate and magnesium hydroxide, may produce a bowel movement in 30 minutes to 6 hours. Others may not take effect for 24 to 48 hours.
- Stimulant laxatives, such as Dulcolax and Senna, may take 6 to 12 hours.
- Stool softeners, such as Docusate, may take 24 to 48 hours.
- Fiber-based laxatives, including Fibercon and Metamucil, can take 12 to 72 hours.
Natural stool softeners
Prunes contain soluble and insoluble fiber.
Doctors often recommend that people struggling with constipation make lifestyle changes to help ease their symptoms.
Many people can find relief from constipation by drinking plenty of water and getting regular exercise.
People can also benefit from eating more fiber. A study from 2014 reports that increasing dietary soluble fiber intake speeds up the transit time and relieves symptoms in people with slow-moving constipation.
People can increase their daily fiber intake by including more fruits and vegetables in their diet. Fiber-rich foods that can help with constipation include:
- Prunes. Prunes can help people stay regular. They contain both soluble and insoluble fiber, which may help absorb water and give body to the stool.
- Apples. Apples are rich in pectin, a helpful soluble fiber. Try including apples as a snack between meals.
- Dark, leafy greens. Vegetables, such as spinach, kale, and collard greens, can fit into many dishes and are an easy way to add fiber and nutrients to a meal.
Side effects of laxatives
All laxatives come with the risk of side effects. Some side effects are temporary, while others may be severe enough to warrant a change in medication.
Common side effects in all types of laxatives are:
- stomach cramps
- bloating or gas
- nausea or vomiting
Some oral stool softeners may cause throat irritation when swallowed.
Other side effects may vary based on the active ingredient in each laxative.
Misusing laxatives, such as taking laxatives for extended periods, may cause severe and potentially dangerous symptoms.
Allergic reactions are also possible with all laxatives. Anyone who is having an allergic reaction or is unsure about their reaction should stop using the laxative and call their doctor.
Importantly, laxatives may interact with other drugs a person is taking. People with constipation who take other drugs should speak with a doctor or pharmacist before taking any laxative.
Occasional constipation is normal. Both stool softeners and other laxatives may provide temporary relief from symptoms, and the choice between them may depend on how quickly a person needs relief.
People may experience side effects or complications from taking certain laxatives. Anyone experiencing side effects that last more than a few days should contact their doctor to find out the cause.