Initially, the low-FODMAP diet is very restrictive: The idea is to cut out all FODMAPs before slowly reintroducing some to determine which you can tolerate. It’s important to work with your health team when making any dietary change to avoid nutritional deficiencies.
3. Cheese, milk, and dairy products
“Dairy is a tricky one: Lactose intolerance can be perceived as a flare of ulcerative colitis,” says Dr. Hong. “One of the things we recommend is if you’re feeling unwell with things you’re eating, try cutting out the dairy. If that does help, then maybe get tested for lactose intolerance, which is an easy test to do and is warranted.”
Even if you don’t think you’re lactose intolerant, there’s another reason consuming dairy could make you feel sick. Lactose is a FODMAP, which might explain why it gives you G.I. symptoms. Everyone reacts to FODMAPs differently, so it’s worth getting tested for lactose intolerance and working through the process of elimination with your medical team.
Ulcerative colitis is not the same as celiac disease, in which gluten triggers the immune system to attack the small intestine. However, some research indicates that people with ulcerative colitis are more likely to also have celiac disease. Alternatively, you might have gluten sensitivity, meaning you don’t have an immune response to gluten but find it causes symptoms including bloating, abdominal pain, diarrhea, and fatigue, all of which can also be symptoms of ulcerative colitis.
A 2014 Inflammatory Bowel Diseases study surveyed 314 people with an IBD—including 122 people with ulcerative colitis—and found that 56.5% reported less bloating while on a gluten-free diet. In addition, 42.6% reported less diarrhea, 41.5% reported less abdominal pain, and 38.3% reported that they had fewer, and less severe, flare-ups.
But don’t start tossing out your favorite cereal just yet. A high-FODMAP carbohydrate called fructan is in many of the same foods as gluten. So cutting out gluten means you’re eliminating many FODMAP foods too, which can be too much of a change to just take on by yourself.
As with all of these foods, it’s a matter of trial and error, and working with a professional can help you figure out what’s going on as safely as possible. “We don’t recommend gluten avoidance per se, and there’s no evidence that gluten worsens IBD,” says Dr. Hong. “If someone’s having symptoms, we’ll go down the list and try avoiding gluten, try avoiding FODMAPs, and if they seem to respond, then we’ll go down that path.”
5. Wine, beer, and other alcoholic beverages
Alcohol stimulates your intestines, which can make diarrhea worse. Plus, the high sugar content in many types of alcohol could also cause diarrhea. In addition, researchers believe the additive sulfite, found in beer, wine, and lager, may worsen symptoms, rather than the alcohol itself—which brings us to the last item on this list.
6. Sulfites and other additives
Researchers have studied the impacts of additives on people with ulcerative colitis. It’s important to mention that research on these additives is preliminary—most have been conducted on animals and the results in mice wouldn’t necessarily replicate in humans. “It’s a big area of study because additives are so prevalent in modern foods,” Dr. Hong says. “But there isn’t some strong evidence saying, ‘These are absolutely out-and-out bad for you.’ But there are thoughts that they could be bad.”
We’ve already mentioned sulfites, which manufacturers often use to lengthen the shelf life of products, including burgers, soft drinks made from concentrate, sausages, canned goods, meats, fish, and dried fruit. Experts theorize sulfites damage bacteria that promote gut health.