Avocados, Garlic & 5 Other Foods That Can Make IBS Worse

If you're wondering why these foods are grouped together, they share a characteristic that makes them difficult to digest for people with IBS. These foods, Kahn tells Bustle, "can provoke symptoms like gas, bloating, abdominal pain, constipation, and diarrhea because they are high in FODMAPs." Never heard of FODMAPs? "FODMAP is an acronym for a group of short-chain carbohydrates that stands for Fermentable Oligo-, Di- and Mono-Saccharides & Polyols. These carbohydrates are known to rapidly ferment in the gut and/or don’t absorb properly in the small intestine," Kahn explains.

Foods in this group have various characteristics that mean they can't be effectively digested by people with IBS. Dr. Zembroski tells Bustle that they all have different issues: legumes — like chickpeas, black beans, lentils and peanuts — contain plant sugars called galacto-oligosaccharides and a protein called lectin, while garlic and onion contain the carbohydrate fructan. All three substances create issues for people with IBS, irritating their digestive systems and causing gas and pain.

Another source of FODMAPs? Avocado. Alas for your brunch plans. Sara Kahn says that avocados are one of the fruits that need to be eliminated in a low-FODMAP diet to manage IBS symptoms. However, she says, it's not meant to be forever. "This is not a long-term diet and we reintroduce foods in a structured manner to determine just which types of carbohydrates are problematic," she tells Bustle. IBS is highly individual; some people may react better to avocado than others.

Stephanie Papadakis, nutritionist and founder of Gut Of Integrity, tells Bustle that when it comes to IBS, one particular kind of fiber is not your friend. "Foods high in insoluble fiber can worsen symptoms," she says. "Insoluble fiber stays intact as it moves through your digestive system, which can be helpful for those with IBS-related constipation because it can get things moving. Soluble fiber, on the other hand, attracts water, which helps remove excess fluid, helping to decrease diarrhea."

Sources of insoluble fiber include bran, whole wheat, potatoes, cauliflower, wheat germ, quinoa, oatmeal, coconut, almonds and walnuts, says Dr. Zembroski.

Banana splits? Nope. Gastroenterologist Dr. Peyton Berookim explains that if you have IBS, "as a general rule, it is best to avoid items that will cause diarrhea or constipation" — and that bananas are definitely one of those questionable items. They're known to cause both diarrhea and constipation, particularly if they're unripe or consumed in larger quantities.

Science goes back on forth on how good dairy is for you, but people with IBS need to follow separate guidelines. Dr. Zembroski tells Bustle that people with IBS should avoid "animal-dairy products containing the milk sugar lactose and the protein casein" — which includes milk, cheeses, and any chocolate involving dairy. There are some cheeses, including brie, cheddar, and camembert, that are low in lactose, but they call contain casein, so they're also classified as high-risk for people with IBS.

Kale is the vegetable of the moment, but it might be off the menu if you have IBS, as are other vegetables of the same class. "Cruciferous vegetables, including kale, cauliflower, Brussels sprouts, and broccoli, contain powerful disease-fighting compounds," says Dr. Zembroski. Unfortunately, he explains, they also contain a carbohydrate called raffinose. It's only broken down in the gut through fermentation, and that can cause a lot of problems if you have IBS.

"Those with IBS can experience visceral hypersensitivity, whereby the nerves in the gut are extra-sensitive. The byproducts of the breakdown of cruciferous vegetables — gas, bloating — can aggravate that hypersensitivity," he says.

Some foods, Papadakis tells Bustle, are actually a good idea for people with IBS because they have high levels of soluble fiber. Berries like strawberries, she notes, are one ideal source of nutrition for people with IBS, because they dissolve in water.

However, some fruits aren't so helpful for a gut with IBS. Apples, apricots and cherries, explains Dr. Zembroski, create irritation because they contain both fructose and a kind of sugar alcohol known as polyols. Polyols "have been shown to trigger gastrointestinal symptoms and act as a natural laxative, increasing gastrointestinal transit time." Experts on IBS at Monash University note that all stone fruits contain polyols, as do pears and mushrooms.

The key factor when it comes to creating a food plan when you have IBS, experts tell Bustle, is patience. "With regards to food, each individual is slightly different and may respond differently to food types," Dr. Berookim tells Bustle. "For this reason I highly encourage my patients to keep a food diary or log so that they can pinpoint which foods trigger their symptoms." Your IBS isn't necessarily the same as anybody else's, so work with your doctor or nutritionist to make sure you find out what triggers your symptoms and what your system can tolerate.