Sweeteners and sugar alcohols with IBS: sorbitol, xylitol, erythritol and stevia

Sugar alcohols are the sweeteners most likely to cause trouble. Monash University calls polyols the most well-documented sweetener relevant to IBS: they are slowly absorbed, draw water into the gut and are fermented in the large intestine, which can cause bloating and diarrhea. Sorbitol, mannitol, xylitol, maltitol and isomalt are the ones to look for, especially in sugar-free gum, mints and candy.

Other sweeteners are less clear-cut. Erythritol behaves differently from other polyols, and stevia is not a polyol at all, but blends and serving sizes matter. This guide walks through each type, how to read a label, and gentle swaps.

These are typical answers. Polyol tolerance is personal, and the reintroduction phase of a low-FODMAP approach is how you find yours.

Polyols, also called sugar alcohols, occur naturally in some fruits and vegetables. Monash notes that stone fruits and mushrooms contain them, and that the two it has studied most are sorbitol and mannitol. Others, such as xylitol, maltitol and isomalt, are added to chewing gum, mints and products marketed as "no sugar".

Polyols are absorbed slowly in the small intestine, so much of what you eat reaches the large intestine, where gut bacteria ferment it. Monash explains that this osmotic and gas-producing effect can cause bloating, pain and changes in bowel habit. In one Monash study, a 10 g dose of sorbitol or mannitol significantly increased symptoms in people with IBS compared with controls.

Whether you react depends on more than the polyol. Monash lists the amount eaten, what else is in the meal, how many other FODMAPs you have had that day, and how sensitive your gut is at the time. Not everyone with IBS needs to avoid all polyols, which is why they are tested one at a time during reintroduction.

Not all polyols behave the same. A randomized, double-blind study of young adult volunteers compared erythritol and xylitol taken in a drink:

• Xylitol at 35 g and 50 g was linked to significant gut symptoms and watery stools compared with table sugar.
• Erythritol at 20 g and 35 g was well tolerated. At 50 g, only nausea and stomach rumbling increased significantly.
• At every amount tested, xylitol caused significantly more watery stools than erythritol.

A separate controlled study found that taking erythritol together with fructose roughly doubled the breath hydrogen response compared with fructose alone, increased watery stools and made gut symptoms worse. The authors concluded that the combination increased carbohydrate malabsorption. That is worth knowing if you use an erythritol-based sweetener in fruit smoothies or with honey.

Both studies were in adults without digestive conditions, so they can’t tell you exactly how your gut will respond. They do show why a sweetener that suits one person in coffee may not suit someone else in a fruit-heavy breakfast.

On safety more broadly, the FDA permits sugar alcohols such as sorbitol, xylitol and erythritol as sugar substitutes. On erythritol specifically, it says the observational studies it reviewed did not establish a causal link to cardiovascular effects.

Not every sugar substitute is a polyol. The FDA lists six high-intensity sweeteners approved as food additives, including aspartame, sucralose and saccharin, and has evaluated GRAS notices for high-purity steviol glycosides and monk fruit extract without questions. It also notes that stevia leaf and crude stevia extracts are not considered GRAS, so the stevia you find in US stores is a purified extract.

Monash’s overview of FODMAPs in foods lists table sugar, maple syrup and rice malt syrup as low FODMAP sweeteners. For more on syrups, see honey, maple syrup and agave. Monash’s general view is that sweeteners are best used as a "sometimes" food, whichever kind you choose.

Monash’s label-reading guide lists sorbitol, mannitol, maltitol, xylitol, isomalt and lactitol as polyol ingredients, and warns that products labeled low sugar or no sugar may use polyols in very high doses. Outside the US, polyols may also appear as E numbers rather than names.

• Look for "-ol" endings in the ingredient list: sorbitol, mannitol, xylitol, maltitol, lactitol, erythritol. Isomalt is the exception to the pattern.
• Watch the laxative warning. Under US rules, a food that could lead to a daily intake of 50 g of sorbitol must say "Excess consumption may have a laxative effect". Monash notes that sugar-free gums and mints often carry a similar statement.
• Check sugar-free gum, mints and candy, which are among the most common sources of polyols.
• Check the back of blends. A packet labeled "stevia" or "monk fruit" on the front may be mostly erythritol.
• Look for inulin and chicory root in "no sugar added" bars and drinks. Monash notes inulin is added as a prebiotic and can cause gas and bloating in some people with IBS.

If polyols don’t suit you, these swaps may help while you work out your tolerance:

• Gum and mints: look for products sweetened with sugar or a non-polyol sweetener, and check the ingredient list for any "-ol".
• Hot drinks: a little table sugar or maple syrup, which Monash lists as low FODMAP, or a pure stevia product without erythritol.
• Baking: table sugar or maple syrup in modest amounts, rather than a polyol-based blend.
• Sweet snacks: Monash lists dark chocolate among low-FODMAP options. See chocolate with IBS and reflux.

Talk to a doctor or registered dietitian if sugar-free products seem to cause ongoing diarrhea or pain, if you are managing blood sugar and want to change sweeteners, or if your symptoms change. A dietitian can help you test polyols one at a time rather than avoiding them all long term. Keeping a food and symptom diary makes those conversations easier.