The Elimination Phase, Week by Week

Before you start: two ground rules

• •This phase is a diagnostic tool, not a lifestyle. Its whole point is to earn a calm gut so reintroduction can tell you something. Plan for 2–6 weeks, not forever.
• •Do it with a dietitian if you can — especially if you have a history of restrictive eating, are pregnant, or have other conditions in the mix. The diet is demanding, and professional guidance keeps it safe and short.

Week 1: swap, don't starve

The goal of week one is replacements, not restriction. Wheat bread becomes sourdough spelt or gluten-free; milk becomes lactose-free milk; onion and garlic become garlic-infused oil, chives, and the green tops of spring onions. You should finish week one eating roughly the same amount of food you started with.

Expect some chaos: you'll discover trigger ingredients in foods you never suspected — stock cubes, spice mixes, "healthy" snack bars sweetened with inulin or honey. Scan first, buy second.

Weeks 2–3: the settling window

Most people who respond to the diet notice a difference somewhere in this window — less bloating by evening, fewer urgent mornings, more predictable days. Keep portions in the low band and watch stacking: several moderate foods in one meal can quietly undo an otherwise clean day.

If nothing has changed by the end of week three despite consistent eating, that's genuinely useful information too — it suggests FODMAPs may not be your main driver, and your next conversation with your clinician can move on to other angles.

Weeks 4–6: hold steady, then move on

Once symptoms have clearly settled, give it another week or two of stability, then start reintroduction. Staying in elimination longer than needed doesn't add benefit — it narrows your diet and your life for no extra information.

The mistakes that stall people

• •Eating low-FODMAP foods in high-FODMAP amounts (a whole avocado, a pile of almonds).
• •Missing hidden onion and garlic in sauces, marinades, and anything labelled "seasoned".
• •Letting the diet shrink to five foods — variety keeps you nourished and keeps the phase sustainable.
• •Skipping the exit: elimination without reintroduction leaves you restricted forever and none the wiser.

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