Polyol sweetener · Polyol · E420
Sorbitol intolerance: symptoms and how to spot it on labels
The short answer
Sorbitol (E420) is a sugar alcohol that the small intestine absorbs poorly, so it draws water into the bowel and ferments — causing gas, bloating, and diarrhea in sensitive people, sometimes from just a few sugar-free sweets. It's a high-FODMAP polyol and a well-known cause of "sugar-free" stomach upset.
What sorbitol is
Sorbitol is a polyol, or sugar alcohol — a sweetener that occurs naturally in stone fruits like apricots, plums, and pears, and is manufactured for use in processed food. It's about half as sweet as sugar, adds bulk, and holds moisture, so it does more than just sweeten.
Why it’s in your food
Manufacturers use sorbitol to sweeten "sugar-free" and "no added sugar" products, to keep foods soft and moist (it's a humectant), and as a bulking agent that replaces the volume lost when sugar is removed. It's cheap, stable, and doesn't spike blood sugar, which is why it's everywhere in diet and dental products.
The science, in plain language
Sorbitol is absorbed slowly and incompletely in the small intestine by passive diffusion, so a large fraction reaches the colon. There it does two things: it pulls water into the bowel (an osmotic, laxative effect) and it's fermented by bacteria into gas. This is why sorbitol has a documented laxative threshold and why Monash and the wider polyol literature classify it as high FODMAP.
What it feels like
Bloating, gas, cramping, and loose stools or diarrhea — often disproportionate to how little was eaten. A few pieces of sugar-free gum or candy can be enough. Because the laxative effect is dose-dependent, symptoms scale quickly with quantity.
What to look for on the label
The same ingredient shows up under several names. On an ingredient list, watch for:
Commonly hides in
- •Sugar-free gum and mints
- •Sugar-free and "no added sugar" candy
- •Diabetic and diet chocolate
- •Sugar-free cough syrups and liquid medications
- •Dried fruit (naturally, especially prunes and apricots)
- •Reduced-sugar baked goods and ice cream
Better-tolerated alternatives
Erythritol is generally much better tolerated than sorbitol — it's also a polyol, but the body absorbs most of it before it reaches the colon, so it's far less likely to ferment or draw in water (Monash rates erythritol low FODMAP at moderate servings). For everyday sweetness, glucose-based options like table sugar, maple syrup, or rice malt syrup avoid polyols entirely. Note that dried fruit is a natural sorbitol source, so a low-FODMAP swap isn't only about avoiding labels.
The bottom line
One of the clearest offenders behind "sugar-free" stomach trouble. High FODMAP and mildly laxative by design — sensitive guts should watch the dose closely.
Frequently asked questions
What are the symptoms of sorbitol intolerance?
Bloating, excess gas, abdominal cramping, and loose stools or diarrhea, typically a few hours after eating sorbitol-containing foods. Because sorbitol has an osmotic, laxative effect, symptoms are dose-dependent — even small amounts in sugar-free gum or sweets can trigger them in sensitive people.
Is sorbitol high FODMAP?
Yes. Sorbitol is a polyol, the P in FODMAP, and Monash University classifies it as high FODMAP. It's poorly absorbed, so it's best limited during the elimination phase and reintroduced carefully when you test the polyol group.
How much sorbitol causes symptoms?
It varies a lot between people, but sorbitol has a relatively low threshold — studies have found that even around 5 grams can cause symptoms in sensitive individuals, and it's cumulative across a day. Sugar-free products can contain several grams per serving, so a few pieces of gum or candy can add up quickly.
Related hidden FODMAPs
This page is for informational purposes only and is not medical advice. Sorbitol is safe for the general population; the FODMAP concerns described here apply to people with IBS or FODMAP sensitivity, and tolerance is individual. FODMAP classifications reflect Monash University testing and the published FODMAP literature. Always work with your doctor or a registered dietitian on dietary changes.