1. Identify the IBS Subtype
Different IBS types need slightly different nutrition approaches:
IBS-D (diarrhea-predominant)
IBS-C (constipation-predominant)
IBS-M (mixed: diarrhea + constipation)
IBS-U (unclassified)
2. General Dietary Strategies for All IBS Patients
a. Low-FODMAP Diet (Most Effective Intervention)
FODMAPs = fermentable carbohydrates that trigger symptoms.
Steps:
Elimination phase (4–6 weeks): Avoid high-FODMAP foods.
Reintroduction phase: Add foods back one at a time to identify triggers.
Personalization phase: Create a long-term diet avoiding only the foods that cause symptoms.
High-FODMAP foods to limit:
Onions, garlic
Beans, lentils
Wheat products
Milk, ice cream
Apples, mango, watermelon
Sweeteners like sorbitol
Low-FODMAP options:
Rice, oats, maize
Chicken, fish, eggs
Lactose-free milk
Carrots, cucumber, green beans
Bananas, grapes, oranges
b. Adequate Fiber Intake (Type matters)
For IBS-C: Increase soluble fiber (helps soften stool).
For IBS-D: Avoid excessive insoluble fiber which worsens diarrhea.
Soluble fiber sources (recommended):
Oats
Chia seeds
Psyllium (best evidence)
Sweet potatoes
Bananas
Avoid too much insoluble fiber:
Wheat bran
Raw vegetables (cabbage, cauliflower)
Nuts in excess
c. Hydration
Aim for 6–8 cups of water/day.
Helps regulate bowel movement, especially in constipation-dominant IBS.
Avoid:
Excess caffeine (triggers cramps and diarrhea)
Energy drinks and sodas
d. Reduce Fatty and Greasy Foods
Fat delays stomach emptying and may increase cramps and diarrhea.
Limit:
Fried foods
Heavy creams
Fast foods
e. Limit Gas-Producing Foods
To reduce bloating and discomfort.
Examples:
Beans
Carbonated drinks
Cabbage, broccoli, onions
Chewing gum (causes air swallowing)
f. Avoid Trigger Foods
Common triggers:
Spicy foods
Caffeine
Alcohol
Chocolate
Artificial sweeteners (sorbitol, mannitol)
Triggers vary per individual → food/symptom diary is helpful.
g. Regular Eating Pattern
Eat small frequent meals rather than large meals.
Avoid skipping meals.
Eat slowly and avoid rushing.
3. IBS-Specific Strategies by Subtype
A. IBS-D (Diarrhea-Predominant)
Focus on:
Soluble fiber (psyllium, oats)
Low-fat diet
Avoid lactose if intolerant
Limit caffeine and spicy food
Low-FODMAP approach
B. IBS-C (Constipation-Predominant)
Focus on:
Increase soluble fiber gradually
Increase fluids
Encourage regular exercise
Warm fluids in the morning (stimulates bowel movement)
Low-FODMAP if gas and bloating occur
Avoid:
Excessive wheat bran (worsens symptoms)
C. IBS-M (Mixed)
Balance fiber intake carefully
Avoid extremes (very high fiber or very low fiber)
Follow personalized low-FODMAP plan
4. Probiotics
Some evidence shows benefit for symptom relief.
Useful probiotics:
Bifidobacterium infantis 35624
Lactobacillus plantarum
Multi-strain probiotics
Food sources:
Yogurt (lactose-free if needed)
Kefir
Fermented foods (in moderation—some may worsen gas)
5. Stress & Lifestyle Management
IBS is strongly linked to the gut–brain axis.
Recommend:
Regular physical activity
Deep breathing exercises
Adequate sleep
Cognitive behavioral therapy (CBT) for severe cases (evidence-based)
6. Supplements (When Needed)
Psyllium (soluble fiber) – best for both IBS-C and IBS-D
Peppermint oil capsules – reduces cramping
Vitamin D – may help symptom control if deficient
Avoid self-prescribing harsh laxatives.