Which Artificial Sweeteners Have a Laxative Effect? A Guide to Sugar Alcohols

November 15, 2025 •

5 min read

According to the NHS, some sweeteners known as polyols, such as sorbitol and xylitol, can cause laxative effects if consumed in large amounts. This happens because the human body does not fully absorb these ingredients, leading to gastrointestinal distress from undigested material.

Quick Summary

An overview of which sugar substitutes can cause diarrhea, gas, and bloating. Focuses on the group of sweeteners called sugar alcohols, their mechanism, and how to avoid discomfort.

Key Points

Sugar Alcohols (Polyols): The primary group of artificial sweeteners known to cause a laxative effect, including sorbitol, mannitol, and xylitol.
Poor Absorption: These sweeteners are not fully absorbed by the small intestine and are fermented by gut bacteria in the large intestine.
Osmotic Effect: Unabsorbed polyols draw water into the colon, which can lead to bloating, gas, and diarrhea.
Dose-Dependent: The severity of the laxative effect is directly related to the quantity consumed and varies significantly among individuals.
Erythritol Exception: Erythritol is better absorbed and generally causes fewer digestive issues in moderate doses compared to other polyols.
Read Labels: Always check ingredient lists for sugar alcohols, which often end in "-ol," to manage consumption and prevent discomfort.
Not All Sweeteners: Non-polyol sweeteners like stevia and monk fruit do not typically cause the same osmotic laxative effects.

Artificial sweeteners are a popular sugar substitute for those looking to manage calorie intake or blood sugar levels. However, a common side effect of many low-calorie sweeteners is gastrointestinal discomfort, including a noticeable laxative effect. The primary culprits are a class of sweeteners called sugar alcohols, or polyols, which are found in many "sugar-free" and "diet" products. Understanding which artificial sweeteners have a laxative effect, why they cause digestive issues, and how to manage your intake can help you avoid unwanted side effects.

Understanding the Laxative Mechanism of Sugar Alcohols

The digestive distress caused by polyols stems from their unique metabolism in the body. Unlike regular sugar, which is readily absorbed in the small intestine, sugar alcohols are only partially absorbed. The portion that remains unabsorbed continues its journey to the large intestine.

Once in the large intestine, these unabsorbed compounds are fermented by the resident gut bacteria. This fermentation process produces gas, which is the cause of bloating and flatulence. Furthermore, sugar alcohols create an osmotic effect, drawing water from the body's tissues into the large intestine. This influx of water softens the stool and stimulates bowel movements, leading to diarrhea. The severity of the laxative effect is highly dependent on the amount consumed and varies significantly among individuals.

Key Artificial Sweeteners with a Laxative Effect

Not all sugar alcohols are created equal when it comes to their impact on digestion. Some are more notorious for their laxative properties than others. Here are some of the most common polyols to be aware of:

Sorbitol: This is one of the most potent sugar alcohols and is even used as a medical laxative. It is naturally found in certain fruits like apples and prunes, but is also a common additive in sugar-free gums, candies, and cough syrups. Its strong osmotic effect makes it a frequent cause of diarrhea when consumed in excess.
Mannitol: Similar to sorbitol, mannitol has a strong laxative effect, and products containing it in high amounts are required to carry a warning label in the US. It is often used as a dusting agent on chewing gum or in other sugar-free foods.
Xylitol: Widely used in sugar-free gum, mints, and diabetic-friendly candies, xylitol is well-known for its digestive side effects. While it is generally tolerated better than sorbitol or mannitol, consuming too much too quickly can lead to gas, bloating, and diarrhea.
Erythritol: This polyol is unique because about 90% is absorbed into the bloodstream before it reaches the large intestine, where it is later excreted in urine. This means it typically causes fewer digestive issues than other sugar alcohols. However, large doses can still induce a laxative effect. The European Food Safety Authority has even set a recommended daily limit to guard against this effect.
Maltitol: Often used to provide a creamy texture in sugar-free chocolates, ice cream, and baked goods, maltitol can cause significant gastrointestinal irritation, bloating, and diarrhea.
Isomalt: This polyol is frequently used in hard candies and other confections. It may cause a laxative effect if consumed excessively.

Comparison of Sugar Alcohols and Their Laxative Potential


Sweetener (Polyol)	Laxative Potential	Common Products	Key Considerations
Sorbitol	High	Sugar-free gum, candy, cough drops, some fruits (apples, prunes)	Strong osmotic effect; used as a medical laxative.
Mannitol	High	Coatings on gum, dietetic foods, pharmaceuticals	Often requires a warning label for excessive consumption.
Xylitol	Medium to High	Sugar-free gum, mints, candies, dental products	Generally tolerated better than sorbitol/mannitol but still a common cause of GI issues.
Maltitol	Medium to High	Sugar-free chocolates, baked goods, ice cream	Can cause significant bloating and diarrhea.
Erythritol	Low to Medium	Baked goods, beverages, tabletop sweeteners	Higher absorption rate means fewer side effects, but large doses can be problematic.
Isomalt	Medium	Hard candies, throat lozenges	Can cause issues with excessive intake.

Managing Digestive Side Effects

For those who experience discomfort from polyols, a few key strategies can help manage and reduce symptoms:

Reduce Intake: The simplest solution is to cut back on the amount of sugar-free products you consume. Since the effect is dose-dependent, a lower dose is less likely to cause a reaction.
Check Labels: Become a savvy shopper by reading the ingredients list. Look for any sweetener ending in "-ol" and be aware of their presence in products. Many manufacturers will also add a required warning label if the product contains enough polyols to cause a laxative effect.
Choose Alternatives: If you are particularly sensitive, opt for sweeteners that are not polyols. Stevia, monk fruit extract, and allulose are generally not associated with the same laxative properties as sugar alcohols.
Gradual Introduction: If you are new to a product with sugar alcohols, start with a small amount and gradually increase it. This allows your body to potentially adapt over time. However, if sensitivity persists, it is best to reduce or eliminate the product.

Other Sweeteners and Digestive Health

While sugar alcohols are the most likely to cause osmotic-related laxative effects, other high-intensity sweeteners are not entirely without digestive impact. Some studies suggest that sweeteners like saccharin and sucralose could alter the composition of gut bacteria. For some sensitive individuals, this microbiome disruption might lead to digestive complaints, though typically not the same potent laxative effect as polyols. The precise effects can vary widely from person to person, and more research is ongoing.

Conclusion: Listening to Your Body

In conclusion, if you've experienced unexplained bloating, gas, or diarrhea after consuming sugar-free products, the culprit is most likely a sugar alcohol. Understanding the specific culprits like sorbitol and mannitol and how their poor absorption leads to an osmotic effect in the gut can help you pinpoint the cause. By carefully reading food labels, moderating your intake, and choosing alternative sweeteners if necessary, you can enjoy the benefits of low-calorie sweeteners without the unwanted digestive consequences. Always listen to your body and consult a healthcare professional if you have persistent or severe digestive issues related to diet.

For more information on sugar substitutes and their health implications, refer to the Mayo Clinic guide on artificial sweeteners.

Frequently Asked Questions

The laxative effect is primarily caused by sugar alcohols, also known as polyols. They are not fully absorbed by the body and are fermented by gut bacteria in the large intestine, which draws water into the colon and can lead to diarrhea.

Yes, sorbitol is a well-known osmotic laxative that is even used medically to treat constipation. It pulls water into the colon, stimulating bowel movements.

Yes, excessive consumption of xylitol can cause digestive problems such as bloating, gas, and diarrhea, particularly when consumed in large amounts or by sensitive individuals.

The potency varies. Sorbitol and mannitol are generally considered to have a stronger laxative effect, while erythritol is often better tolerated and causes fewer issues in moderate doses. The effect is also dose-dependent.

Unlike polyols, non-nutritive sweeteners like sucralose and aspartame are not typically associated with a strong osmotic laxative effect. However, some individuals may experience digestive issues, and research suggests these can alter the gut microbiome.

To reduce side effects, start by moderating your intake of products containing sugar alcohols, read food labels, and stay hydrated. If you are very sensitive, you may consider avoiding them completely.

While generally not harmful in the short term, excessive consumption leading to chronic diarrhea can cause dehydration and electrolyte imbalances. For most healthy individuals, the effect is temporary discomfort.

The gas and bloating are caused by the fermentation of unabsorbed sugar alcohols by bacteria in your large intestine. This process produces gas, leading to a feeling of fullness and discomfort.

The laxative threshold varies, but adverse effects can occur from doses as low as 10 grams for some individuals. Many products with high polyol content carry a warning label about potential laxative effects, signaling high consumption.

Natural sweeteners like stevia leaf extract and monk fruit extract are not polyols and do not typically cause a laxative effect. Allulose is another non-polyol, low-calorie sweetener that is absorbed differently and avoids the same issues.