Constipation is a common condition that affects 27% of the population. Harsh over-the-counter laxatives are not the only solution for the straining, stomach pain, and frustration associated with constipation. Read on to learn more about many natural laxatives, such as Aloe vera, probiotics, and coffee, that are just as effective as commercial products.
What Are Laxatives?
Laxatives are substances that stimulate bowel movements. They are used in the treatment of constipation. You can buy most laxatives over-the-counter without a prescription.
Constipation is difficulty passing stools. It is defined by one or more of the following symptoms:
- Fewer than 3 bowel movements per week
- Straining more than 25% of the time
- Passing less than 35 grams of stool per day [R]
There are 2 types of constipation:
- Primary/Functional Constipation, which is caused by colon issues, such as slow movement or incomplete passing of stool.
- Secondary Constipation, which is caused by medications or diseases including cancer, hypothyroid, and depression [R].
Dietary Causes of Constipation
Constipation in the United States is partly caused by the American diet. Diets with the following characteristics cause constipation:
- High in saturated fat (>30g per day) including red meat and fast food [R]
- Low in fiber (<25g per day) [R]
- High in dairy including cheese and chocolate [R, R, R]
- High in processed grains including white bread [R]
How Do Laxatives Work?
Laxatives stimulate bowel movements in different ways. While some increase moisture or bulk of the stool, others act directly on the intestines. Below are the most common types of laxatives:
- Bulk laxatives are fiber supplements that increase the volume of feces, causing the intestines to contract.
- Osmotic laxatives increase the amount of water in the intestines, softening the stool and making it easier to pass.
- Stimulant laxatives contain chemicals that stimulate the muscles in the colon to contract, pushing the feces out.
- Softener laxatives increase the amount of water taken up by feces, making it softer as it passes through the intestines [R].
Stool softener vs. Laxatives
A stool softener is a type of laxative. The word “laxative” is an umbrella term for all substances that ease constipation. Stool softeners increase the water content of feces, which reduces friction as it moves through the intestines.
Natural laxatives include foods, herbs, minerals, and supplements. They are often gentler than chemical laxatives.
1) Aloe Vera
While Aloe vera is well-known for treating burns, it is also a natural laxative. In a study (DB-RCT) of 28 healthy adults, the laxative effects of Aloe vera were stronger than those of a popular stimulant laxative (phenolphthalein) [R].
Another study (DB-RCT) on 38 patients with chronic constipation reported that Aloe vera worked as a laxative when combined with two other natural supplements (celandin and psyllium) [R].
Aloe latex, a yellow substance found under the plant skin, is no longer sold as a laxative in the United States. The molecule (anthraquinone) that gives it its laxative properties can cause serious side effects in humans and cancer in rats [R, R].
You can buy Aloe vera juice or water in most supermarkets. Products made from Aloe vera gel don’t contain anthraquinone and most commercially available whole leaf extracts have been treated with charcoal (decolorized) to remove the harmful molecule [R].
Senna is a flowering plant in the legume family and a common stimulant laxative. Senna products, such as Senokot and Ex-Lax, can be bought over-the-counter [R].
In a study (DB-RCT) of 77 elderly patients suffering from constipation, those treated with senna had more frequent bowel movements, softer stools, and decreased straining compared to those taking a prescription laxative (Lactulose) [R].
The stimulant effect comes from sennosides, or senna glycosides, derived from the plant. A rat study found sennosides increase water in the intestines and contractions in the colon [R].
Sennosides are also found in rhubarb, giving it similar laxative properties to Senna [R].
Prunes are famous for their laxative effects, and for good reason.
In one study (SB-RCT), 40 constipated people were given either prune (50 g/day) or psyllium (a natural bulk laxative). The prunes were not only more effective but also healthier and more pleasurable to ingest [R].
Prunes contain 6.1g of fiber per 100g, which contributes to their laxative effects. However, prune juice, which is devoid of fiber, also has laxative effects [R].
Although sorbitol is available over-the-counter at most pharmacies, it’s also found naturally in apples, pears, and peaches.
4) Castor Oil
In a study of chronically constipated rest home residents, castor oil decreased the symptoms of constipation, including straining, hard stools, and an incomplete passing of feces [R].
The laxative component of castor oil is ricinoleic acid. This acid is absorbed by the intestines and induces contractions, pushing stool through the colon [R].
In another study (DB-RCT), 300 constipated adults were given probiotics (Lactobacillus plantarum, Bifidobacterium breve, B. animalis)for 30 days. The probiotics caused a decrease in hard stools, which eased stool passing. Participants also experienced a decrease in constipation symptoms, such as bloating, stomach pains, and general discomfort [R].
Flaxseeds are small, brown seeds that are increasingly popular in America for their high-fiber, low-carb, superfood qualities. They are also an effective natural laxative.
In a study of 26 young adults, subjects were given flax fiber supplements (9g/day), which acted as a bulk laxative [R].
7) Olive Oil
In a 4-week study (DB-RCT), 50 constipated adults were given 4mL/day of olive oil, flaxseed oil or mineral oil. Olive oil reduced symptoms of constipation, such as incomplete passing, hard stool, and colonic obstruction better than flaxseed oil and just as well as mineral oil [R].
Another study (RCT) of 120 patients found that olive oil was the best pretreatment for patients receiving colonoscopies. Olive oil cleared out the colon and was the most pleasant substance to ingest [R].
Besides containing high levels of insoluble fiber and sorbitol, apples are also full of pectin, a gel-like sugar used to set jams and jellies. Pectin is a soluble dietary fiber and natural laxative found in some fruits, including apples and oranges [R, R, R].
In one study (RCT), 80 patients suffering from constipation were given 24g/day of pectin for 4 weeks. The pectin group had shorter stool transit time and an increase in healthy gut bacteria [R].
An apple a day may just keep the doctor away.
9) Oat Bran
Bran is the hard outer layer that coats cereal grains. Oat bran is eaten as a hot cereal, in bread, or mixed into smoothies.
A study (SB-RCT) of 30 patients in a geriatric hospital found that dietary supplementation with 7-8 g of oat bran per day was a healthy alternative to laxatives. It caused a 59% decrease in laxative use among patients [R].
Psyllium is stool softener made from the husk of the plant Plantago ovato. It can be bought over-the-counter and is used as a food thickener, dietary supplement and natural laxative [R].
Psyllium is high in soluble fiber, which allows it to absorb water and form a gel-like substance in the colon [R].
In a study (DB-RCT) of 177 subjects with chronic constipation, subjects were given 5.1 g psyllium per day experienced greater stool output than those given a prescription laxative (docusate sodium) [R].
Although magnesium is frequently used for constipation, there is little clinical data proving its effectiveness. Regardless, milk of magnesia (magnesium hydroxide) is one of the most commonly used osmotic laxatives in Canada. Both experts and user reviews support its use for constipation [R, R, R].
In an Italian study (RCT) involving 118 patients with chronic constipation, those who drank 2 liters of mineral water with magnesium every day had a higher stool frequency. In another study (RCT), milk of magnesia (20mL daily) improved bowel movement better than bulk laxatives in 64 patients with chronic constipation [R, R].
When ingested, most formulations of magnesium are poorly absorbed in the gut (especially the hydroxide and oxide), which causes more water to go into the intestines — making it an osmotic laxative. It also activates a hormone (cholecystokinin) and enzyme (nitric oxide synthase), all of which combined stimulate bowel movements. Magnesium is supplemented in the form of a saline laxative, typically as magnesium hydroxide (milk of magnesia) and magnesium citrate [R].
One review reported that coffee affects the colon like a 1,000 calorie meal due to its effect on a hormone called gastrin. Gastrin stimulates cells that secrete acid, thus stimulating digestion and causing intestinal movement [R, R].
Although caffeine plays a role in causing intestinal muscle contractions, it isn’t the main laxative substance in coffee. One study of 12 healthy subjects found that while caffeinated coffee was 60% stronger in laxative action than hot water, decaffeinated coffee was 37% stronger, which accounts for most of the difference. [R].
High levels of caffeine stimulate the kidneys to expel more water and can thus worsen constipation if an individual is dehydrated [R].
There’s a reason ginger ale is the universal home remedy for indigestion and nausea. In a study (DB-RCT) of 48 chronically constipated patients, a laxative mixture containing powdered ginger increased the weekly frequency of bowel movements [R].
Like most fruits, mango has a lot of fiber, making it an effective bulk laxative. However, n a pilot study, constipated subjects who consumed 300 g of mango for 4 weeks experienced improved stool frequency, consistency, and shape compared to subjects who consumed an equal amount of fiber. The researchers speculate mango may contain polyphenols that reduce intestinal inflammation, but more research is needed [R].
15) Sugar Substitutes
Common natural substances used as artificial sweeteners that have a laxative effect include mannitol, xylitol, and sorbitol. They are found in chewing gum, candies, and flavored drinks. Research suggests only excessive consumption of sugar substitutes will have a laxative effect on the digestive system [R].
Some laxatives on the market are sugar substitutes, including Lactulose and Lactitol. These are not natural [R].
Multiple surveys, including one of 1,705 Japanese women and one of 2,807 elderly Asian people, reported a correlation between increased consumption of rice and decreased levels of constipation [R, R].
Drinking enough water is crucial to maintaining general health, especially of the digestive system.
In a study (RCT) of 117 chronically constipated adults, all subjects consumed 25 g of fiber per day. The group that drank 1.5-2.0 liters of water per day had significantly increased stool frequency compared to the control group, which only consumed 1.0 liter [R].
Water may only be helpful for those who are experiencing constipation due to dehydration. For constipation caused by more complex reasons, such as disease, water may not be an effective treatment. A study of 883 elderly people showed that there was no correlation between daily fluid intake and frequency of constipation [R].
18) Not Baking Soda
Baking soda has traditionally been used as a home remedy to relieve constipation. However, there is no scientific research to support the use of baking soda as a laxative.
Fast Acting Laxatives
Certain situations require fast-acting laxatives. Stimulant laxatives act the fastest since they directly act on the smooth muscles. These include [R]:
- Aloe vera
- Castor oil
In extreme cases of constipation, marked by vomiting or anal bleeding, consult a doctor.
Constipation and laxative use is especially common in the elderly, but strong laxatives can lead to dehydration, malnutrition, and weight loss. Switching to natural, mild laxatives can be safer and healthier [R].
Bulk laxatives, such as dietary fiber, are the gentlest for long-term use. Natural bulk laxatives include:
- Oat Bran
- Green Leafy Vegetables
Diet For Constipation
Diets that are high in dietary fiber increase stool frequency and promote weight loss [R].
‘Fiber’ actually includes many indigestible carbohydrates. However, they are usually grouped into two general types [R]:
- Soluble fiber is soft material that absorbs water to form a gel-like substance in the intestines. It is found in legumes, nuts, and oats.
- Insoluble fiber doesn’t dissolve in water and is indigestible, thus adding bulk to stool. It is found in wheat bran, flax, and most fruits and vegetables.
A meta-analysis of 17 studies on irritable bowel syndrome patients found that while soluble fiber was effective in treating constipation, the insoluble fiber had no significant benefits, and sometimes worsened the condition by causing an obstruction [R].
While all fiber is healthy and a good way to prevent constipation, if you are already constipated a diet high in soluble fiber eases symptoms better than insoluble fiber. To avoid side-effects like bloating and gas, start at a low dosage and increase over several weeks to 20-30 g per day [R].
The side effects of natural laxatives are the same as those for commercial laxatives because many of them act similarly. Side effects include [R]:
- Stomach pain
The fastest-acting natural laxatives, stimulant laxatives, are not recommended for use in the elderly, pregnant women, and young children. These laxatives, which include senna, aloe vera, and castor oil, may cause diarrhea and lead to dehydration and/or malnutrition in these populations.
Laxatives and Weight Loss
The use of laxatives for weight loss has not been proven effective. Laxatives are often misused or abused by those seeking to lose weight, leading to many dangerous health consequences.
Laxative abuse causes dehydration. The body responds by retaining water and becoming bloated (edema), leading to temporary weight gain. This can reinforce further laxative abuse, creating a dangerous cycle [R].
Using laxatives for weight loss can lead to changes in the digestive tract, such as potassium deficiency and acid/base imbalances. There are also structural changes in the cells lining the colon and, in some cases, allergic reactions [R, R].
The risks outweigh any temporary benefits of using laxatives for weight loss. Healthier alternatives should be pursued instead.
Limitations and Caveats
Many of the studies discussed here had small sample sizes.
Subjects in these studies may have also been experiencing different levels and causes of constipation, which may have affected the results.
The laxative effects of rice have not been extensively researched in humans and may be caused by other conflicting variables.
Natural laxatives should be taken in moderation. In extreme cases of constipation, consult a doctor.
There isn’t much research on the effects of laxatives on medication absorption, however, some cases of interference have been reported and caution should be exercised. Laxatives like senna and soluble fibers like psyllium can decrease the absorption of drugs and reduce their effects [R, R].
Talk to your doctor or pharmacist about any prescription or over-the-counter drugs you are taking to see which laxatives are right for you.
Genetics and Genetic Predispositions
While primary constipation is often a result of temporary conditions, secondary constipation can be a symptom of a disease, possibly with genetic influence [R].
Secondary cases can be caused by genetic mutations related to many aspects of the digestive process. Genes that encode for gut neurotransmitters and receptors (the NOS1, TACR1, TACR3, and KIT genes) could be involved in secondary constipation [R, R].
Although genes may play a role, constipation is also caused by lifestyle choices and diet, which are influenced by one’s family and environmental factors.
Before heading to the pharmacy to pick up commercial laxatives when you’re feeling backed up, try some of these easy home remedies:
- Make caffeinated coffee
- Brew some hot ginger tea
- Eat plenty of raw fruits
- Eat vegetables cooked in olive oil
- Drink prune juice
- Try doing yoga or Pilates in your home [R]
- Drink 8-16 oz of water every 2 hours
Forms of supplementation
These natural laxatives can be bought over-the-counter:
- Senna can be taken orally in liquid, strip, or tablet form.
- Sorbitol can be taken orally as powder, liquid, or capsules or through the rectum as an enema.
- Psyllium can be taken orally in powder, capsules, liquid, or wafer form.
Users have reported constipation relief by eating leafy vegetables and drinking prune and apple juices.
Other users suggest eliminating dairy and low-fiber carbohydrates, such as white bread.
Some users found success by going to the bathroom whenever they have “the urge” or else the stool becomes dry and hard to pass.