HEALTH TOPICS 
One of the most frequent questions that patients with inflammatory bowel disease (IBD) ask is: what should I eat?
It is clear that in addition to genetic factors, certain environmental factors, including diet, may trigger the excessive immune activity that leads to intestinal inflammation in IBD, which includes both Crohn’s disease and ulcerative colitis (UC). However, the limited number and high variability of studies have made it difficult to confidently advise patients regarding which specific foods might be harmful and which are safe or may actually provide a protective benefit.
New IBD dietary guidelines
To help patients and providers navigate these nutritional questions, the International Organization of IBD (IOIBD) recently reviewed the best current evidence to develop expert recommendations regarding dietary measures that might help to control and prevent relapse of IBD. In particular, the group focused on the dietary components and additives that they felt were the most important to consider because they comprise a large proportion of the diets that IBD patients may follow.
The IOIBD guidelines include the following recommendations:
| Food | If you have Crohn’s disease | If you have ulcerative colitis |
| Fruits | increase intake | insufficient evidence |
| Vegetables | increase intake | insufficient evidence |
| Red/processed meat | insufficient evidence | decrease intake |
| Unpasteurized dairy products | best to avoid | best to avoid |
| Dietary fat | decrease intake of saturated fats and avoid trans fats | decrease consumption of myristic acid (palm, coconut, dairy fat), avoid trans fats, and increase intake of omega-3 (from marine fish but not dietary supplements) |
| Food additives | decrease intake of maltodextrin-containing foods | decrease intake of maltodextrin-containing foods |
| Thickeners | decrease intake of carboxymethylcellulose | decrease intake of carboxymethylcellulose |
| Carrageenan (a thickener extracted from seaweed) | decrease intake | decrease intake |
| Titanium dioxide (a food colorant and preservative) | decrease intake | decrease intake |
| Sulfites (flavor enhancer and preservative) | decrease intake | decrease intake |
The group also identified areas where there was insufficient evidence to come to a conclusion, highlighting the critical need for further studies. Foods for which there was insufficient evidence to generate a recommendation for both UC and Crohn’s disease included refined sugars and carbohydrates, wheat/gluten, poultry, pasteurized dairy products, and alcoholic beverages.
How would observing these guidelines help?
The recommendations were developed with the aim of reducing symptoms and inflammation. The ways in which altering the intake of particular foods may trigger or reduce inflammation are quite diverse, and the mechanisms are better understood for certain foods than others.
For example, fruits and vegetables are generally higher in fiber, which is fermented by bacterial enzymes within the colon. This fermentation produces short-chain fatty acids (SCFAs) that provide beneficial effects to the cells lining the colon. Patients with active IBD have been observed to have decreased SCFAs, so increasing the intake of plant-based fiber may work, in part, by boosting the production of SCFAs.
However, it is important to note disease-specific considerations that might be relevant to your particular situation. For example, about one-third of Crohn’s disease patients will develop an area of intestinal narrowing, called a stricture, within the first 10 years of diagnosis. Insoluble fiber can worsen symptoms and, in some cases, lead to intestinal blockage if a stricture is present. So, while increasing consumption of fruits and vegetable is generally beneficial for Crohn’s disease, patients with a stricture should limit their intake of insoluble fiber.
Specific diets for IBD?
A number of specific diets have been explored for IBD, including the Mediterranean diet, specific carbohydrate diet, Crohn’s disease exclusion diet, autoimmune protocol diet, and a diet low in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs).
Although the IOIBD group initially set out to evaluate some of these diets, they did not find enough high-quality trials that specifically studied them. Therefore, they limited their recommendations to individual dietary components. Stronger recommendations may be possible once additional trials of these dietary patterns become available. For the time being, we generally encourage our patients to monitor for correlations of specific foods to their symptoms. In some cases, patients may explore some of these specific diets to see if they help.
New guidelines are a good place to start
All patients with IBD should work with their doctor or a nutritionist, who will conduct a nutritional assessment to check for malnutrition and provide advice to correct deficiencies if they are present.
However, the recent guidelines are an excellent starting point for discussions between patients and their doctors about whether specific dietary changes might be helpful in reducing symptoms and risk of relapse of IBD.
I am a 63 year old woman who has suffered from Crohns since my early 20’s. At that time I had chronic diarrhea and lots of pain on one side of my lower abdomen.
I was finally as diagnosed in my late 40’s with a bowel obstruction and a fistula. I did not respond to treatment and continued to have “mini obstructions that calmed down only with fasting. My doctor and I believed I was a ticking time bomb for a catastrophic event.
Soon after, I had surgery to remove 4 inches of bowel and fistula repair. My surgeon hand inspected my entire bowel during surgery and found no further damage.
He and my gastroenterologist were so impressed with the lack of damage throughout my bowel for the past 20 years, they agreed they did not want me on medication. I have had no problems whatsoever for the past 11 years.
I eat a meticulous vegan diet and get daily exercise; mostly walking and hiking. I average 6-8 miles daily when walking .
I love the food I eat and do not feel deprived. Fatty foods, fast food, candy just sound like a dose of pain.
My colonoscopies are clean. I know it is accepted that there is no cure for Crohn’s , but I have had no medications or symptoms for so long, I believe I no longer have the disease.
In response to AGoldstein I’d say, Yes, stress doesn’t help but in my case the problem was controlled by a radical change in diet and strict conformity what I found worked. Getting the malady under control helped to reduce the stress particularly stress from the challenges of managing bowel control when travelling.
I suffered for years from IBD (colitis) and then, realising that the standard treatments had all sorts of unfortunate side effects I decided to tackle it with dietary change. Cut out all grain based carbs (bread, biscuits & the like; eliminate refined sugar and processed foods and eliminate all milk products. It worked. Haven’t suffered since the change (15 – 20 years ago) and I survive very well on fresh vegetables, salads, eggs, some meat, and fresh fruit. Lots of green smoothies with organic greens, fruit and seeds such as linseeds, pumpkin seeds and sunflower seeds soaked in water 24 hours. Now 76, fit & well.
Wow Kenneth!
My IBD (possible ulcerative colitis) symptoms were 95% improved by going to a low-sugar, gluten-free and lactose-free diet. I suffered for years with bouts of diarrhea for 1-3 days per week. My gastroenterologist neglected to suggest this. I decided to try it myself. I have been really well for five years. I am 82 years old.
I have IBD and milk was the worst thing to ingest as well as certain vegetables and fruits. Especially cabbage and bananas. My anal area would get inflamed, then the diahrea. What did help was a mood stabilizer. When I started taking that, the irritable bowel stopped. They say the gut and brain are closely connected. But yes. Mood stabilizer works and I can now eat almost anything except bananas.
This article is missing associations with food allergies, which could be the cause of incorrectly diagnosed IBD or IBS.
Recent observations by doctors at Grand River Hospital (Kitchener Ontario Canada) on the consumption of edible marijuana (THC and CBD components), used for pain and nausea control, have identified elevated instances of IBD flare ups in both cancer and non cancer patients (no one specific cancer types identified during the observations). The observations require further study, but were high enough to these doctors, to advise their patients to use other methods of intake or other medications. The Federal Government recently legalized the use of marijuana in Canada, as such, funding to conduct a fulsome study was refused. I hope someone can get funding to further study the effects of THC, CBD on the patients with IBD.
What about microscopic colitis – have any studies looked at the effect of diet? Or do you not consider that IBD?
Isn’t stress level (i.e., the gut-brain connection) a complicating factor for individuals who are trying to determine whether specific food ingredients are helpful or harmful to their IBD? Shouldn’t the also be tracking their stress level? If so, what is the best way to assess stress?