What are the basic diet recommendations for mixed Irritable Bowel Syndrome (IBS)?

Basic Diet Recommendations for Mixed Irritable Bowel Syndrome (IBS)

For patients with mixed IBS, a low FODMAP diet supervised by a dietitian is the most evidence-based dietary approach after implementing general dietary advice. 1, 2

General Dietary Recommendations

• Have regular meals and take time to eat - avoid skipping meals or leaving long gaps between eating 1
• Drink at least 8 cups of fluid per day, especially water or other non-caffeinated drinks such as herbal teas 1
• Restrict tea and coffee to 3 cups per day 1
• Reduce intake of alcohol and carbonated drinks 1
• Limit fresh fruit to 3 portions per day (approximately 80g per portion) 1
• Consider limiting high-fiber foods, especially insoluble fiber (such as whole-meal flour, high-fiber breads, bran cereals) 1, 3
• Reduce intake of "resistant starch" found in processed or recooked foods 1
• For patients with bloating and gas, try adding oats and linseeds (up to 1 tablespoon per day) 1
• Avoid sorbitol, an artificial sweetener found in sugar-free products, especially if diarrhea is predominant 1

Low FODMAP Diet Approach

For patients who don't respond to general dietary advice, a low FODMAP diet should be considered as a second-line approach:

1. Restriction Phase (4-6 weeks):

   • Substantially reduce intake of fermentable carbohydrates 1, 2
   • Consider taking a daily multivitamin during this phase 1
   • If no improvement after 4-6 weeks, discontinue and try alternative treatments 1

2. Reintroduction Phase (6-10 weeks):

   • Systematically reintroduce individual FODMAP groups 1
   • Increase doses gradually over 3 days for each food group 1
   • Common triggers include wheat, milk, and garlic 1
   • Document responses to create a personalized long-term diet 1, 2

3. Personalized Maintenance Phase:

   • Based on reintroduction results, liberalize diet to include tolerated foods 1
   • This improves nutritional adequacy and quality of life 1, 2

Fiber Supplementation

• For mixed IBS, consider soluble fiber supplementation, particularly psyllium (ispaghula) 1, 3
• Start with low doses (3-4g/day) and increase gradually to avoid bloating 2, 3
• Avoid insoluble fiber supplements like wheat bran as they may worsen symptoms 1, 3

Additional Supportive Measures

• Regular physical activity can help manage IBS symptoms 1, 2
• Create time for relaxation and stress management 1
• Consider probiotics for at least 4 weeks to assess effectiveness 1, 2
• If symptoms persist despite dietary changes, consult with a gastroenterologist for additional treatment options 1

Important Considerations

• The low FODMAP diet should be implemented with guidance from a dietitian to ensure nutritional adequacy 1, 2
• For patients with moderate to severe psychological symptoms, a Mediterranean diet may be more appropriate than a strict low FODMAP diet 1
• Some studies suggest that traditional IBS dietary advice may be as effective as a low FODMAP diet 4
• Avoid self-directed exclusion diets without professional guidance as they may lead to nutritional deficiencies 1