Low FODMAP diet in Ulcerative Colitis: fad or fact?

Waldbieser J. Fodmap diets for ulcerative colitis. EverydayHealth.com. https://www.everydayhealth.com/ulcerative-colitis/ulcerative-colitis-low-fodmap-diet/. Accessed January 26, 2023.

For most people who have seen a medical professional, diet and exercise are one of the most recommended non-drug options. With so many different diets seen on social media sites, it can be confusing to decide what options work well for you.

Some popular specialty diets that are followed include10:

  • Flexitarian
  • Vegetarian
  • Pescatarian
  • Religious or cultural dietary preferences
  • Lacto-ovo vegetarian
  • Vegan

However, a popular diet that is used in irritable bowel syndrome (IBS) to reduce gas, bloating, and diarrhea is the low-FODMAP diet.9 You might often confuse IBS with ulcerative colitis and may follow the low-FODMAP diet regardless of the most current evidence.

This article will discuss when the low-FODMAP diet should be considered a treatment option when managing ulcerative colitis.

What is Ulcerative Colitis?

The first thing to establish. Ulcerative colitis is a chronic (reoccurring or lasting for a long time) condition that affects the colon and rectum.6 The condition is inflammatory, meaning your body’s immune system attacks its tissues causing inflammation. Inflammation is typically a good thing and is useful for repairing the body, however, some bodies have uncontrolled amounts of inflammation leading to symptoms.

When it comes to ulcerative colitis, common symptoms include 6:

  • diarrhea with or without blood
  • abdominal cramps
  • mucous

Other symptoms that may be seen often when dealing with blood loss and difficulties digesting food over a long time may include:

  • weight loss
  • urgency
  • anemia

Endoscopy is a key tool medical professionals use to help differentiate between ulcerative colitis and similar conditions such as Crohn’s disease, irritable bowel syndrome, and infections.6

Changes in when and how often symptoms appear can be different based on how severe the condition is. You might ask yourself, “how does my diet come to play”, especially since your digestive system is a key component of ulcerative colitis. 

What is a low-FODMAP diet? (what does it consist of, how does it work)

What does the low-FODMAP diet look like? It is a diet that includes foods that are low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.7 FODMAPs are types of carbohydrates that are poorly absorbed in the small intestine.

NOTE: different people react differently to various types of foods. One person who experiences bloating or diarrhea from certain FODMAP foods, may not experience the same effects with other FODMAP foods.

The reason why FODMAP foods may cause gas, bloating, and diarrhea7:

  • they pull water into the gut, which can cause bloating, distension, and diarrhea.
  • are fermented by gut bacteria, they can produce gases that can lead to symptoms such as gas, bloating, and abdominal discomfort.
  • can stimulate the gut’s motility, which means they can affect the way the muscles in the gut contract and move, leading to diarrhea

Examples of FODMAP foods1:

  • fructans: wheat, rye, barley, etc.
  • fructose: most juices, apples, grapes, etc.
  • galactooligosaccharides: beans, soy, chickpeas, etc.
  • lactose: animal milk products, yogurt, cheese, etc.
  • polyols: avocado, blackberries, etc.

These foods are taken away from your diet and each item is slowly reintroduced to see if they cause symptoms. Please consult a dietician or medical professional for a complete list of foods that are considered high in FODMAP.

When does it work?

A low FODMAP diet has shown to be effective in patients with irritable bowel syndrome, but not Irritable Bowel Diseases (which includes ulcerative colitis). Currently, there isn’t much convincing evidence to suggest that diets that restrict certain foods are beneficial for people with ulcerative colitis.2 However, the diet may be considered temporary depending on the symptoms you have.

It is important to discuss with your doctor and dietitian to discuss which diets you might want to try. It is also especially important to confirm if you have ulcerative colitis.

Alternatives options/diets

Other diets you might want to consider for ulcerative colitis include:

  • Anti-inflammatory diet4: diet with foods that may have anti-inflammatory properties (fruits, vegetables, whole grains, lean protein, and healthy fats)
  • Elimination diet8: diets removing certain foods (i.e., dairy, gluten, and processed foods that trigger symptoms for you). These foods may be reintroduced, when symptoms improve.
  • High-fibre diet3,8: diets high in fibre may promote bowel regular bowel movements and reduce diarrhea

Foods to potentially avoid include5:

  • Spicy foods
  • High-fat foods
  • Sugary foods
  • Lactose
  • Difficult to digest/Insoluble fibre foods

Regardless of which diet you’re considering; it is important to discuss it with your dietitian and doctor. They can help you develop a diet plan to reduce your symptoms while ensuring the diet is safe and has all the nutrients you need.


  1. Barbara Bolen PD. Avoid certain high-fodmap food types to treat your IBS. Verywell Health. https://www.verywellhealth.com/what-are-the-fodmap-types-1944697. Published August 29, 2022. Accessed January 25, 2023.
  2. Cox SR, Lindsay JO, Fromentin S, et al. Effects of low fodmap diet on symptoms, fecal microbiome, and markers of inflammation in patients with quiescent inflammatory bowel disease in a randomized trial. Gastroenterology. 2019;158(1). doi:10.1053/j.gastro.2019.09.024
  3. Fritsch J, Garces L, Quintero MA, et al. Low-fat, high-fiber diet reduces markers of inflammation and dysbiosis and improves quality of life in patients with ulcerative colitis. Clinical Gastroenterology and Hepatology. 2020;19(6). doi:10.1016/j.cgh.2020.05.026
  4. Keshteli AH, Valcheva R, Nickurak C, et al. Anti-Inflammatory Diet Prevents Subclinical Colonic Inflammation and Alters Metabolomic Profile of Ulcerative Colitis Patients in Clinical Remission. Nutrients. 2022;14(16):3294. Published 2022 Aug 11. doi:10.3390/nu14163294
  5. Vandever L. What foods should you avoid with ulcerative colitis? Healthline. https://www.healthline.com/health/ulcerative-colitis-foods-avoid#insoluble-fibers. Published June 22, 2022. Accessed January 25, 2023.
  6. Rubin DT, Anathakrishnan AN, Siegel CA, Sauer BG, Long MD. ACG clinical guideline: Ulcerative colitis in adults : Official Journal of the American College of Gastroenterology: ACG. LWW. https://journals.lww.com/ajg/fulltext/2019/03000/acg_clinical_guideline__ulcerative_colitis_in.10.aspx. Published March 2019. Accessed January 22, 2023.
  7. Staudacher HM, Whelan K. The low FODMAP diet: recent advances in understanding its mechanisms and efficacy in IBS. Gut. 2017;66(8):1517-1527. doi:10.1136/gutjnl-2017-313750
  8. Tomasello G, Mazzola M, Leone A, et al. Nutrition, oxidative stress and intestinal dysbiosis: Influence of diet on gut microbiota in inflammatory bowel diseases. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2016;160(4):461-466. doi:10.5507/bp.2016.052
  9. Veloso HG. FODMAP diet: What you need to know. FODMAP Diet: What You Need to Know | Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/wellness-and-prevention/fodmap-diet-what-you-need-to-know. Published December 29, 2021. Accessed January 22, 2023.

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