Do artificial sweeteners give you diarrhea? Breaking down the science of sugar substitutes

October 25, 2025 •

5 min read

According to Harvard Health, artificial sweeteners like sorbitol, mannitol, and xylitol are considered some of the biggest dietary offenders for causing or worsening loose stools. For many people, the answer to do artificial sweeteners give you diarrhea? is a resounding yes, primarily due to how certain types are processed—or rather, not fully processed—by the human body.

Quick Summary

An in-depth look at how various artificial sweeteners, especially sugar alcohols, can trigger digestive side effects like diarrhea. It explains the osmotic effect and gut microbiota changes, helping you identify which sweeteners might be causing trouble and what steps to take.

Key Points

Sugar alcohols cause diarrhea via the osmotic effect: Compounds like sorbitol and xylitol are poorly absorbed and draw water into the large intestine, resulting in loose stools.
Gut microbiome disruption is a factor: Some artificial sweeteners, including sucralose and neotame, may negatively alter the balance of gut bacteria, contributing to digestive issues like diarrhea.
Sugar alcohols are part of FODMAPs: For sensitive individuals, especially those with IBS, sweeteners like sorbitol and mannitol are high-FODMAP carbohydrates that can trigger symptoms.
Personal tolerance varies widely: The amount of sugar alcohols or other sweeteners that cause digestive upset differs significantly from person to person.
Check labels for hidden sweeteners: Sugar alcohols are often found in sugar-free gum, candy, and diet products; awareness is key to managing symptoms.
Other food additives and drinks can also contribute: Factors like caffeine, high-fat foods, and dairy can worsen the laxative effect of sweeteners.

Understanding the Link: Why Artificial Sweeteners Can Cause Diarrhea

Many individuals turn to artificial sweeteners as a way to enjoy sweet foods and beverages without the added calories and sugar. However, some experience unpleasant gastrointestinal side effects, with diarrhea being one of the most common. The reason for this isn't a one-size-fits-all explanation, as different types of sweeteners affect the body in different ways. The primary culprits are a class of sugar substitutes known as sugar alcohols, or polyols.

The Osmotic Effect: A Laxative by Another Name

Sugar alcohols, such as sorbitol, mannitol, and xylitol, are not fully absorbed by the small intestine. When consumed in large amounts, these unabsorbed compounds travel to the large intestine, where they create an osmotic effect. This means they draw water into the colon, which loosens bowel movements and can lead to diarrhea. This effect is so well-established that products containing significant amounts of sorbitol or mannitol are required to carry a label warning that "excess consumption may have a laxative effect".

For most people, a small amount of sugar alcohols might not cause any issues. However, sensitivity varies from person to person. As noted by the American Dietetic Association, consuming more than 50 grams of sorbitol or 20 grams of mannitol per day can trigger diarrhea. This can happen surprisingly quickly when consuming multiple servings of sugar-free gum, candy, or diet products throughout the day.

Other Sweeteners and Their Impact on the Gut

While sugar alcohols are the most well-known cause of sweetener-induced diarrhea, other non-nutritive sweeteners may also play a role, albeit through different mechanisms. Some studies suggest that sweeteners like sucralose and saccharin can disrupt the gut microbiota—the community of beneficial bacteria that aid in digestion.

A healthy, balanced gut microbiome is essential for smooth digestion. When this balance is disturbed by certain artificial sweeteners, the proliferation of 'bad bacteria' can lead to gastrointestinal distress, including bloating, gas, and, in some cases, diarrhea. Emerging research, such as a 2024 study published in Frontiers in Nutrition, investigated the effects of newer sweeteners like neotame and found they could also negatively impact the gut's bacterial balance and intestinal wall integrity, potentially leading to increased leakiness.

The FODMAP Connection

For those with sensitive digestive systems, particularly individuals with Irritable Bowel Syndrome (IBS), understanding FODMAPs is crucial. The term FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. FODMAPs are a group of carbohydrates that are poorly digested by some people and can cause significant digestive issues. Sugar alcohols like sorbitol and mannitol are polyols and therefore fall under the FODMAP category. A diet low in FODMAPs has been shown to improve diarrhea symptoms in IBS patients.

A Comparison of Common Sweeteners and Their Digestive Effects

To better understand which sweeteners to be cautious of, here is a comparison of some of the most common artificial sweeteners and their potential impact on digestion.


Sweetener Type	Examples	Digestive Impact	Notes
Sugar Alcohols (Polyols)	Sorbitol, Mannitol, Xylitol, Erythritol	High potential for causing diarrhea, especially in large amounts. Works via the osmotic effect, drawing water into the colon.	Often found in sugar-free gum, candy, and mints. High-dose consumption can trigger severe laxative effects.
Sucralose	Splenda	Moderate potential. Some research links it to disrupting the gut microbiome, which can lead to bloating, gas, and diarrhea.	Sensitivity varies; some individuals report digestive issues, while others experience none.
Aspartame	Equal, NutraSweet	Lower potential compared to sugar alcohols. Some reports and studies suggest it can cause stomach discomfort and other symptoms, but the link to diarrhea is less direct.	Often found in diet sodas and low-calorie desserts. Concerns are more focused on potential long-term health risks and other side effects.
Saccharin	Sweet'N Low	Low potential, but some individuals with sulfa allergies may experience adverse effects like diarrhea.	One of the oldest artificial sweeteners; studies initially linked it to cancer in rats, but this was later disproven in humans.
Stevia	Stevia	Low to moderate potential. While generally well-tolerated, some people experience digestive discomfort like bloating or diarrhea, particularly with higher intakes.	A natural, plant-derived sweetener, but like other sugar substitutes, overconsumption can sometimes be an issue.

How to Manage and Prevent Sweetener-Related Diarrhea

If you suspect that artificial sweeteners are causing you digestive problems, there are several steps you can take. The most effective method is often elimination and observation.

Read Labels Carefully: Check the ingredients list for sugar alcohols like sorbitol, xylitol, and mannitol, especially in sugar-free gum, candies, and diet products. For general awareness, the list of FODMAPs also includes many other items to watch for if you are particularly sensitive.
Keep a Food and Symptom Diary: Track what you eat and any digestive symptoms you experience. This can help you identify specific sweeteners or products that are causing issues.
Reduce Intake: If you love sugar-free products, try cutting back. Sometimes, simply reducing the quantity is enough to alleviate symptoms without having to eliminate them completely.
Consider Alternatives: If you find you are highly sensitive, exploring other, natural sweeteners (in moderation) or simply learning to reduce your preference for overly sweet tastes might be a good long-term strategy.

Conclusion: The Bottom Line on Artificial Sweeteners and Digestive Health

While artificial sweeteners offer a low-calorie alternative to sugar, their impact on digestive health is not to be overlooked. Certain sweeteners, most notably sugar alcohols, have a well-documented laxative effect due to poor absorption and an osmotic action in the gut. Other sweeteners, while not as directly linked to diarrhea, may still disrupt the gut's delicate bacterial balance and cause discomfort in sensitive individuals.

The key to managing any potential side effects is to understand your personal tolerance. Reading ingredient labels, keeping track of your symptoms, and moderating your intake are all practical steps to ensure you can enjoy the benefits of these sweeteners without the unpleasant consequences. For individuals with chronic digestive issues like IBS, identifying and reducing your intake of FODMAPs, including sugar alcohols, can be particularly beneficial.

Remember that responses to food additives can be highly individual. What causes one person distress might have no effect on another. By paying attention to your body's signals, you can make informed dietary choices that support your digestive well-being.

Sources

Harvard Health. Is something in your diet causing diarrhea? August 8, 2023.
News-Medical.Net. Sucralose: Safety and Evidence. August 21, 2023.
Medical News Today. Which foods can cause diarrhea? January 24, 2024.
Healthline. 10 Types of Foods That Can Cause Diarrhea. July 15, 2024.
Newsweek. Common Sweetener May Damage Gut and Cause Diarrhea. April 24, 2024.
Quora. Why do some artificial sweeteners have a laxative effect? May 31, 2019.
MedicineNet. Artificial Sweeteners List, Side Effects, Brands, Dangers.
Mayo Clinic. Diarrhea - Symptoms and causes. January 18, 2025.

Frequently Asked Questions

Sugar alcohols, also known as polyols, are the most common cause of diarrhea from artificial sweeteners. This includes sorbitol, mannitol, xylitol, and erythritol, which are often found in sugar-free gum, candies, and mints.

The amount varies by individual. Some people are highly sensitive, while others can tolerate more. Generally, large amounts, such as over 50 grams of sorbitol or 20 grams of mannitol per day, are more likely to cause issues.

Yes, for some people. Diet soda often contains a combination of artificial sweeteners, and sometimes caffeine, which is a stimulant. This combination can increase the likelihood of digestive issues, including diarrhea.

No. Different sweeteners have different effects. Sugar alcohols are known for their osmotic, laxative effect, while some non-nutritive sweeteners like sucralose might disrupt the gut microbiome.

FODMAPs are a group of poorly absorbed carbohydrates, and polyols (sugar alcohols) are a type of FODMAP. For individuals with a sensitivity, particularly those with Irritable Bowel Syndrome (IBS), consuming high-FODMAP foods can lead to diarrhea.

While the body might adapt slightly, the osmotic effect of sugar alcohols is a physiological process that doesn't significantly change with prolonged use. For those sensitive to sweeteners, continued consumption often leads to continued symptoms.

A good way to check is to keep a food and symptom diary, tracking your intake of sweetened products and any digestive symptoms you experience. Alternatively, try a short-term elimination diet, cutting out all artificial sweeteners to see if your symptoms improve.