Green Onion / Scallion (white part)
Vegetables · Alliums
No. One white bulb weighs about 5 g and carries 0.22 g of fructans, which is enough for a red rating from a piece of vegetable most people would call trim. The green tops of the same plant are rated green at a tablespoon, so the difference between a safe spring onion and a red one is decided by your knife.
Last updated 4 September 2026Serving sizes for green onion / scallion (white part)
One bulb, about 5 g, is the tested amount, and it is rated red.
Tested serving sizes
| Serving | Amount | Main FODMAP | Rating |
|---|---|---|---|
| 1 bulb | 5 g | Fructans 0.22 g |
Breakdown for 5 g
Is green onion / scallion (white part) low FODMAP?
Fructans are what an allium stores in its bulb, so they are concentrated at the pale end and thin out along the leaf. The striking part is the weight involved: 0.22 g of fructans arrives in 5 g of food, more than twice the 0.1 g at which fructans start counting. Chopped onion reaches 0.4 g of fructans, but it takes 10 g of onion to get there. Gram for gram, the little white bulb sits in much the same territory as the vegetable you have already given up.
Green Onion / Scallion (white part) and IBS: what to know
The exposure people miss is not a dish built on spring onion. It is the ordinary habit of chopping a bunch from end to end and tipping the lot into the pan. Recipes that ask you to separate whites and greens almost always send the whites in first, into hot oil, which is exactly where the base of a stir-fry, a congee or a noodle soup is built. Restaurant kitchens rarely make that split at all, and because fructans dissolve into the cooking liquid, straining the pieces out of a broth leaves the load behind in the bowl.
Gut-friendly ways to eat green onion / scallion (white part)
Cut where the pale stem turns dark and firm, and keep the tops. For the sweet aromatic base the bulb was providing, ginger fried in oil covers more of that ground than any allium substitute, with the green tops added at the end for freshness. Sliced chives handle the raw garnish. When you are buying, thin bunches with small bulbs are better value than fat ones, since you are paying by weight for the part that goes in the bin.
Frequently asked questions
Which part of a spring onion is low FODMAP?
The dark green leaf. It has its own entry in this guide, rated green at one tablespoon chopped, while the bulb at the base is red at a single 5 g bulb. Cut at the point where the stem stops being pale, and be strict about it, because the tender pale-green section just above the root behaves like bulb rather than leaf.
Does taking the white bulbs out before serving help?
Not in anything wet. Fructans move into water, so a broth or a braise keeps what the bulbs gave it long after the pieces are lifted out. Oil is the exception, which is the whole principle behind garlic-infused oil: the flavour transfers and the fructans do not. A bought, well-strained infused oil is the reliable version of that trick.
Are spring onion bulbs as bad as onion for IBS?
By weight they are close, and the difference in practice is that a bulb is small enough to seem harmless. Two or three of them chopped into a dish for one person is a real fructan dose, delivered by something that looked like a garnish. If onion is a known trigger for you, treat the white ends the same way.
Can I use one white bulb in a dish shared between four people?
The data does not describe a portion that small, since one whole bulb is already the tested amount and it is rated red. Splitting it four ways is untested guesswork. It is also not worth much, because a quarter of a bulb contributes almost nothing to a shared dish. Build the flavour from oil and greens instead.
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