Irritable Bowel Syndrome (IBS) is a chronic and often life-disrupting brain-gut disorder that affects millions, especially women. IBS is marked by a range of symptoms from abdominal pain to irregular bowel habits, as well as mood symptoms like anxiety or depression in some cases. About two-thirds of people experience gut symptoms first, while for others, mood symptoms may appear initially. The core symptoms are abdominal pain and altered bowel habits, but understanding IBS goes deeper—factors like microbiome diversity, neurotransmitters like serotonin, and gut motility issues play major roles. Though complex, IBS can often be managed by combining effective dietary interventions with lifestyle changes like stress management and regular exercise.
Dietary Recommendations for IBS Management
When it comes to diet, some interventions are particularly effective for IBS with diarrhea (IBS-D), whereas IBS with constipation (IBS-C) may require additional support beyond diet alone. Here’s a look at key dietary approaches proven to help with IBS symptom management.
Increase Soluble Fiber: A Long-Term Solution for IBS
How to Do the Diet
Increasing soluble fiber in your diet is a simple yet powerful way to support regular bowel movements and ease abdominal pain. Soluble fiber absorbs water in the gut, forming a gel-like substance that softens stool and eases passage. Incorporate foods like oats, barley, and fruits such as pears, figs, and apples. Flax seeds, hazelnuts, and sunflower seeds are also high in soluble fiber and can be easily added to your daily meals.
Pros
- Great for improving bowel regularity, especially in IBS-C.
- Soluble fiber is generally well-tolerated and has a mild effect on bloating.
- Rich in nutrients and supports overall health.
Cons
- Insoluble fiber, such as that found in wheat bran, may worsen symptoms, so avoid these types of fiber.
- In the beginning, high-fiber diets can cause some bloating as the gut adjusts.
Expected Results
For many, adding soluble fiber helps improve bowel regularity and reduces abdominal pain. In fact, a study on kiwis found that eating two per day improved bowel frequency in those with IBS-C, likely due to its high soluble fiber content.
Gluten-Free Diet: Reducing Abdominal Pain and Improving Quality of Life
How to Do the Diet
Following a gluten-free diet means eliminating all gluten-containing foods, including wheat, rye, and barley. Many processed foods contain hidden gluten, so always check labels. Some safe, gluten-free grains include rice, quinoa, and oats labeled “gluten-free.”
Pros
- Helps reduce abdominal pain and improve the quality of life for some people with IBS.
- Particularly effective for those with IBS-D, as gluten-free diets often reduce loose stools.
- Gluten-free options are now widely available, making it easier to stick to this diet.
Cons
- Not as effective for overall symptom relief as the Low FODMAP or SSRD diets.
- Does not significantly affect the microbiome for most people, though those with gluten sensitivity may see improvements.
- Can lead to nutrient deficiencies if not carefully balanced, as gluten-free products are sometimes low in fiber and other nutrients.
Expected Results
Individuals with IBS-D often experience fewer loose stools and decreased abdominal pain. While the gluten-free diet may not transform microbiome diversity, those sensitive to gluten could see some microbiome improvements and better long-term symptom control.
Low FODMAP Diet: Highly Effective for IBS Symptom Relief
How to Do the Diet
The Low FODMAP diet involves eliminating high-FODMAP foods (like certain fruits, vegetables, dairy, and grains) for four weeks. After this period, reintroduce foods one by one, tracking symptoms for three days after each food to determine which ones are best tolerated. A dietitian or healthcare provider can offer guidance and improve adherence.
Pros
- Shows an impressive 65-70% success rate in reducing IBS symptoms.
- Particularly beneficial for those with IBS-D, reducing pain and bloating.
- Customizable, as tolerated foods are added back in, allowing a personalized approach.
Cons
- May reduce beneficial Bifidobacterium in the gut after four weeks, as many FODMAP foods support this bacteria.
- Not sustainable long-term if highly restrictive, as reintroducing FODMAP foods can be challenging for some people.
- Requires careful planning and can be difficult to manage alone without professional guidance.
Expected Results
Many people with IBS find relief from pain and bloating within the first few weeks. While the Low FODMAP diet is highly effective during active phases, without reintroduction, symptoms can relapse after six months. For those who follow the Low FODMAP diet under professional supervision, outcomes are often more successful, and the diet helps maintain symptom management longer.
Limiting Tryptophan: Aiming to Improve Motility and Mood
How to Do the Diet
Limiting tryptophan means reducing foods high in this amino acid, such as animal proteins, legumes, and dairy. A target of 13 mg/kg of body weight or less is recommended for this approach, helping to keep serotonin levels more stable. However, keep protein intake balanced to avoid overall deficiency.
Pros
- May decrease motility, reducing diarrhea in IBS-D.
- Beneficial effects on mental health, as it may reduce neuroinflammatory symptoms and support mood.
- Low tryptophan intake can work alongside a Low FODMAP diet for those with diarrhea and anxiety.
Cons
- Low tryptophan can mean limiting protein, which may impact muscle mass and energy levels.
- Some people may struggle to maintain a balanced diet with adequate protein intake.
Expected Results
Lowering tryptophan can improve both GI and mood symptoms for IBS-D sufferers. This can be especially helpful for those who experience anxiety as part of their IBS symptom cluster. Reduced tryptophan can also mean reduced serotonin-related motility issues, which may decrease diarrhea frequency.
Starch and Sucrose Reduced Diet (SSRD): Effective for IBS-C and Weight Management
How to Do the Diet
SSRD involves eliminating all sucrose-containing foods, refined cereals, and certain processed foods, while allowing one serving of whole grains per day. Lean proteins, fiber-rich alternatives, and a variety of low-sugar fruits and vegetables are encouraged. Prolonged chewing of high-protein and high-fat meals helps with starch breakdown and digestion.
Pros
- Non-inferior to Low FODMAP for GI symptom relief.
- Shows additional benefits for weight management, reducing BMI and sugar cravings.
- Supports bowel regularity, especially helpful for those with IBS-C.
Cons
- Not as widely researched as the Low FODMAP diet.
- Lack of reintroduction guidelines may make it challenging to maintain long-term.
Expected Results
Studies show SSRD can lead to better weight control, reduce cravings, and lessen constipation symptoms. For those with IBS-C, this diet’s effects on regularity and weight loss are beneficial, making it an appealing option for those needing dual support.
Combining Low FODMAP and SSRD for Comprehensive Support
While Low FODMAP and SSRD both offer substantial benefits for IBS symptoms, some may find combining elements of each useful. SSRD’s focus on reduced sucrose and starch can be paired with Low FODMAP restrictions, creating a hybrid approach. This can address symptoms of diarrhea, constipation, gas, and bloating, while also reducing some IBS-associated symptoms like back pain, headaches, and joint pain.
Expected Results
Combining these diets can yield comprehensive GI relief and better consistency in symptoms. However, strict adherence and professional support are key, as without reintroduction protocols, a complete return of symptoms can be common within six months.
Conclusion
Dietary strategies play a major role in managing IBS, but other therapies such as stress management, medications, and nutritional supplements may also be necessary for full symptom control. Comprehensive stool analysis, food sensitivity testing, and cortisol evaluations are valuable tools that can further customize treatment. Remember, IBS is a chronic condition and often requires ongoing management—what works for one person may not work for another, so stay patient and persistent in finding what helps you feel your best. A healthcare professional can provide guidance in navigating these dietary and lifestyle changes, offering individualized support to improve your quality of life and long-term symptom management.
Disclaimer
The information provided in this blog and throughout the website is intended for educational purposes only and should not be considered, or used as a substitute for, medical advice. The content is not meant to diagnose, treat, or cure any medical condition. This blog does not constitute the practice of any medical, nursing or other professional health care advice, diagnosis or treatment. Always consult with a qualified healthcare provider before making any changes to your health regimen or starting new treatments, and never disregard professional medical advice or delay seeking care because of something that you have read on this blog, website or in any linked materials. Your individual needs and circumstances should be evaluated by a medical professional to ensure safe and appropriate care. If you are experiencing a medical emergency, please call 911 or call for emergency medical help on the nearest telephone immediately.
References
Algera, Joost P., Maria K. Magnusson, Lena Öhman, Stine Störsrud, Magnus Simrén, and Hans Törnblom. “Randomised Controlled Trial: Effects of Gluten‐free Diet on Symptoms and the Gut Microenvironment in Irritable Bowel Syndrome.” Alimentary Pharmacology & Therapeutics 56, no. 9 (September 29, 2022): 1318. https://doi.org/10.1111/apt.17239.
Black, Christopher J., Heidi M. Staudacher, and Alexander C. Ford. “Efficacy of a Low FODMAP Diet in Irritable Bowel Syndrome: Systematic Review and Network Meta-Analysis.” Gut 71, no. 6 (June 2022): 1117–26. https://doi.org/10.1136/gutjnl-2021-325214.
Chojnacki, Cezary, Tomasz Poplawski, Aleksandra Blonska, Paulina Konrad, Jan Chojnacki, and Janusz Blasiak. “The Usefulness of the Low-FODMAP Diet with Limited Tryptophan Intake in the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome.” Nutrients 15, no. 8 (April 11, 2023): 1837. https://doi.org/10.3390/nu15081837.
Gearry, Richard, Shin Fukudo, Giovanni Barbara, Barbara Kuhn-Sherlock, Juliet Ansell, Paul Blatchford, Sarah Eady, et al. “Consumption of 2 Green Kiwifruits Daily Improves Constipation and Abdominal Comfort—Results of an International Multicenter Randomized Controlled Trial.” The American Journal of Gastroenterology 118, no. 6 (December 20, 2022): 1058. https://doi.org/10.14309/ajg.0000000000002124.
Huang, Kai-Yue, Feng-Yun Wang, Mi Lv, Xiang-Xue Ma, Xu-Dong Tang, and Lin Lv. “Irritable Bowel Syndrome: Epidemiology, Overlap Disorders, Pathophysiology and Treatment.” World Journal of Gastroenterology 29, no. 26 (July 14, 2023): 4120. https://doi.org/10.3748/wjg.v29.i26.4120.
Jent, Sandra, Natalie Sara Bez, Joyce Haddad, Loan Catalano, Kim Stefanie Egger, Michela Raia, Giulia Simona Tedde, and Gerhard Rogler. “The Efficacy and Real-World Effectiveness of a Diet Low in Fermentable Oligo-, Di-, Monosaccharides and Polyols in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis.” Clinical Nutrition 43, no. 6 (June 2024): 1551–62. https://doi.org/10.1016/j.clnu.2024.05.014.
Nagarajan, Neeraja, Amanda Morden, Danielle Bischof, Elizabeth A. King, Martin Kosztowski, Elizabeth C. Wick, and Ellen M. Stein. “The Role of Fiber Supplementation in the Treatment of Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis.” European Journal of Gastroenterology & Hepatology 27, no. 9 (September 2015): 1002–10. https://doi.org/10.1097/MEG.0000000000000425.
National Institute of Diabetes and Digestive and Kidney Diseases. “Eating, Diet, & Nutrition for Irritable Bowel Syndrome - NIDDK.” Accessed October 30, 2024. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/eating-diet-nutrition.
Nordin, Elise, Per M. Hellström, Johan Dicksved, Erik Pelve, Rikard Landberg, and Carl Brunius. “Effects of FODMAPs and Gluten on Gut Microbiota and Their Association with the Metabolome in Irritable Bowel Syndrome: A Double-Blind, Randomized, Cross-Over Intervention Study.” Nutrients 15, no. 13 (July 5, 2023): 3045. https://doi.org/10.3390/nu15133045.
Roth, Bodil, Mohamed Nseir, Håkan Jeppsson, Mauro D’Amato, Kristina Sundquist, and Bodil Ohlsson. “A Starch- and Sucrose-Reduced Diet Has Similar Efficiency as Low FODMAP in IBS—A Randomized Non-Inferiority Study.” Nutrients 16, no. 17 (September 9, 2024): 3039. https://doi.org/10.3390/nu16173039.
So, Daniel, Amy Loughman, and Heidi M. Staudacher. “Effects of a Low FODMAP Diet on the Colonic Microbiome in Irritable Bowel Syndrome: A Systematic Review with Meta-Analysis.” The American Journal of Clinical Nutrition 116, no. 4 (June 21, 2022): 943. https://doi.org/10.1093/ajcn/nqac176.
Staudacher, Heidi M., Sophie Mahoney, Kim Canale, Rachelle S. Opie, Amy Loughman, Daniel So, Lauren Beswick, Chris Hair, and Felice N. Jacka. “Clinical Trial: A Mediterranean Diet Is Feasible and Improves Gastrointestinal and Psychological Symptoms in Irritable Bowel Syndrome.” Alimentary Pharmacology & Therapeutics 59, no. 4 (February 2024): 492–503. https://doi.org/10.1111/apt.17791.