Common IBS symptoms include constipation, diarrhoea, bloating and stomach cramps, but it can also cause back pain, urinary issues and nausea. Photo / 123rf
There’s no cure for irritable bowel syndrome, but you can manage the symptoms by adapting your diet and avoiding red-flag foods.
Irritable bowel syndrome may not be a club anyone wants to be part of, but many of us are finding that we’ve been accepted into its ranks without ever applying.
“Irritable bowel syndrome, or IBS, is a common condition which affects the gastrointestinal system,” explains Dr Vikram Murthy, a GP and the co-founder of Harley Street clinic Murthy Health. “Symptoms can include constipation, diarrhoea, bloating and stomach cramps, but it may also cause back pain, urinary issues, nausea, flatulence, and you may pass mucus too.”
The cause remains unknown, Murthy says. “We do know that it has some link to family history, and also that it can be triggered by anxiety, stress and certain foods.”
There is currently no cure, but all is not lost. In fact, while medicines can help, “diet is the main factor that can control symptoms”, Murthy says. And, as a general rule, the foods which fall into the camp known as FODMAPS – short-chain carbohydrates – are the ones to restrict or avoid completely.
Keep reading to learn more about how diet can affect IBS – and the foods to avoid.
“FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides and polyols,” says Eve Kalinik, a nutritional therapist and the author of Happy Gut, Happy Mind.
“They’re a group of carbohydrates and sugars that are not completely digested or absorbed in the gut. Instead, once eaten, they can ferment in your intestines, potentially producing those unpleasant symptoms from bloating to cramping that plague many IBS sufferers.”
FODMAPS come in five categories:
Gluten gets a bad reputation, but it is not always the enemy, says Dr Emily Leeming, a nutrition and microbiome scientist and the author of Genius Gut. “Some people with IBS report feeling better on a gluten-free diet, but this isn’t the case for everyone,” she says.
In fact, if bread worsens your IBS symptoms, its gluten content may be a red herring: “For some wheat-containing foods like bread and pasta – which contain high levels of both gluten and one or more FODMAP – it can seem like gluten is triggering issues, when in fact it’s the FODMAP.”
Studies suggest that for most IBS sufferers who find food containing gluten a trigger, the enemy is actually fructans, a type of sugar in FODMAP foods (see list above).
“Dairy can be aggravating for people with IBS because they may struggle to digest lactose, a natural sugar found in milk products,” says Kalinik.
Fermented milk products like hard cheese or yogurt may be better tolerated, she says. “This is because during the fermentation process, the lactose is mostly negated.”
When faced with a cheeseboard, self-control is still advised. “Even with fermented dairy, it can be a case of being dose-specific to the individual,” says Kalinik.
Beans and legumes are high in fibre and, if you are suffering from dysbiosis, or an imbalanced microbiome, high-fibre meals can create gas or discomfort, explains nutritionist Rhian Stephenson. They also contain another category of FODMAP – galactooligosaccharides, or GOS.
These foods aren’t inherently unhealthy, stresses Stephenson. “In fact, they are extremely important for the overall health of our microbiome and our nutrient intake. The problem only arises when we have an imbalance in our gut bacteria.”
Soaking beans and legumes overnight, then rinsing before cooking, makes them easier for some (but not all) IBS sufferers to digest.
A third of IBS sufferers say that alcohol makes their symptoms worse, Dr Leeming says. Some alcohol also contains FODMAPs so, if you are sensitive to those and find alcohol a trigger, she suggests you avoid rum and red wine.
Clear spirits like gin and vodka are lower in FODMAPs, but “even a small amount of alcohol can act like an irritant to the gut barrier lining, and can affect how well your gut digests and absorbs nutrients”, Leeming explains.
“Spicy foods can act as an irritant to the gut, and many individuals with IBS will already have more irritation or inflammation than those without IBS,” explains Stephenson. Again, though, don’t throw out the balti.
“It’s important to look at the type of spicy food you’re eating,” Stephenson says. “Takeaways or shop-bought spicy meals may also have added chemicals, flavourings, sugars, and emulsifiers that can exacerbate IBS.” You might find homemade curry less aggravating.
Countless surveys have linked fatty and deep-fried foods to IBS symptoms. In one survey, more than half of respondents felt their symptoms were triggered when they ate fatty or fried foods.
“Deep-fried foods are difficult to digest,” Stephenson explains. “They’re often also ultra-processed, so can be fried in unhealthy, rancid oils, and be accompanied by higher amounts of sugar, preservatives, or emulsifiers, which can add to their potential effects on digestion.” Try grilling or air frying instead.
Mixed news for those who cannot wake up without a cup. One study showed that those without IBS who drank coffee were 16% less likely to develop the condition than those who didn’t. The opposite applies for those who already have IBS, however.
“The caffeine in coffee can stimulate the gut, so food moves faster through your system and that can cause diarrhoea in those with sensitive guts,” Leeming says.
The cause may be located deep within your gut microbiome. “In some of my own research, we found that coffee was one of the foods most strongly linked to gut microbiome composition,” Leeming says. Coffee drinkers tend to have higher microbiome diversity.
Still, Leeming adds: “If you have IBS and find caffeine to be a trigger for you, try switching to decaf or herbal tea. Peppermint tea contains menthol, found in higher amounts in peppermint oil capsules, which acts as an antispasmodic, easing sensitivity and pain.” We’ll raise a mug to that.
These include:
Most of the time, explains Kalinik, they move through the gut without incident. In fact, they can be a boon “because some of them are rich in prebiotics and they can have a positive impact on the health of our gut microbiome. When they move through the small intestine, they naturally attract water and, when reaching the large intestine, act as a fuel source for our gut microbes.”
For IBS sufferers, however, they can prove problematic. “People with IBS can have problems with transition time through the gut. Their gut wall can be more sensitive and they may also have some level of ‘dysbiosis’ or imbalance of the gut microbiome,” explains Kalinik.
It’s likely a combination of one or more of those factors that makes high-FODMAP foods an aggravating factor, causing symptoms like bloating, diarrhoea or constipation.
Sorbitol and xylitol are sugar alcohols, or polyols, found naturally in various plants, but they’re also produced commercially as artificial sweeteners in foods such as sugar-free chewing gum, mints and other low-calorie products. One review of studies found that people with IBS reported symptoms such as flatulence, bloating and abdominal discomfort, even when consuming lower amounts than people without IBS.
Cashews and pistachios are both high in FODMAPs, which can trigger IBS symptoms, even in small serving sizes. Stick to macademia nuts, walnuts, peanuts and pecans, which are all low-FODMAP.
Cooking vegetables makes them easier to digest, but the gold standard dietary intervention for managing IBS symptoms, according to a study published in the journal Gut, is the low-FODMAP diet.
Designed to help IBS sufferers identify the precise foods and FODMAP categories that trigger their symptoms, it involves the following steps:
It’s not an easy process, warns Kalinik: “It’s not to be undertaken without the guidance of a qualified practitioner and not for a long period of time, either, as it is these very same foods that help to support the health of the gut.”