Elimination Diet for IBS: The Step-by-Step Protocol That Actually Works
Elimination Diet for IBS: The Step-by-Step Protocol That Actually Works
By Dr. Onikepe Adegbola, MD PhD — Johns Hopkins-trained physician-scientist
An elimination diet is the gold standard for identifying YOUR personal food triggers. Generic food lists tell you what triggers MOST people — but your body is unique. The low FODMAP elimination protocol identifies exactly which FODMAPs you react to and which you tolerate fine.
Key Takeaways
- The elimination phase lasts 2-6 weeks — NOT forever
- If symptoms don't improve in 6 weeks, the problem isn't food (investigate SIBO, stress, etc.)
- The reintroduction phase is MORE important than the elimination phase
- Most people react to only 1-2 FODMAP categories — you don't need to avoid all of them long-term
- FODMAP digestive enzymes support both phases of the diet
Phase 1: Elimination (2-6 Weeks)
- Remove ALL high-FODMAP foods simultaneously
- Eat from the approved low FODMAP food list (see our grocery list)
- Track symptoms daily (1-10 scale for bloating, pain, stool quality)
- Take FODMAP enzymes with every meal for extra support
- Goal: establish YOUR symptom baseline
Phase 2: Reintroduction (6-8 Weeks)
Test ONE FODMAP category at a time, 3 days per challenge:
- Fructose: 1 tbsp honey in water → increase to 2 tbsp → 3 tbsp
- Lactose: 1/4 cup milk → 1/2 cup → 1 cup
- Fructans (garlic): 1/4 clove → 1/2 clove → 1 clove
- Fructans (wheat): 1/2 slice bread → 1 slice → 2 slices
- GOS: 2 tbsp chickpeas → 1/4 cup → 1/2 cup
- Sorbitol: 2 dried apricots → 4 → 6
- Mannitol: 1/4 cup mushrooms → 1/2 cup → 1 cup
Rest 3 days between challenges. If a category triggers symptoms, mark it and move on.
Phase 3: Personalization (Lifelong)
Now you know YOUR specific triggers. Avoid those and freely eat everything else. This is the sustainable, long-term diet — NOT the restrictive elimination phase.
Support your personalized diet with FODMAP enzymes (for accidental exposure) and daily probiotics (for ongoing gut health).
See our reintroduction guide and FODMAP stacking article.
Work with a registered dietitian for best results. This article is educational only.
