Irritable bowel syndrome (IBS) is a common intestinal disorder that produces distressing symptoms like abdominal pain, significant bloating, and altered bowel movements that can shuttle between diarrhea and constipation.
While changing what you eat won’t cure you, an evidence-based approach called the low-FODMAP diet is the most frequently prescribed food plan to help relieve IBS symptoms. Studies show it can reduce symptoms for the majority of patients. However, because of certain challenges and risks associated with the low-FODMAP diet, it’s worth talking to an expert before you try it.
The low-FODMAP diet addresses four types of fermentable carbohydrates: oligosaccharides, disaccharides, monosaccharides, and polyols (collectively referred to as FODMAPs). While the names sound somewhat abstract, the foods found within these groups are often too familiar to those with digestive woes.
Oligosaccharides are present in foods like wheat, beans, garlic, and onions, while the disaccharide lactose is prevalent in dairy products like ice cream and milk. Monosaccharides refer to foods with excess fructose, and are found in items like apples, mangos, and honey. The final group, sugar alcohols, are found in some artificially sweetened products like chewing gum, and are naturally present in foods like avocados and mushrooms.
Though the FODMAP carbohydrates can trigger digestive discomfort for anyone when consumed in large amounts, much smaller portions can worsen symptoms for those with IBS.
A multiphase approach to a low-FODMAP diet
The low-FODMAP diet is meant to be undertaken in three phases. In the first phase, all high-FODMAP foods are eliminated from the diet for an extended period of time, often four to six weeks. In phase two, you systematically reintroduce restricted foods, noting how well you tolerate increasing quantities of the foods you’re reintroducing. Phase three is the personalization phase, in which you only avoid foods in quantities that cause symptoms.
This multiphase process can be complex and confusing, and requires substantial food knowledge. For instance, most varieties of soymilk are high-FODMAP. Extra-firm tofu, on the other hand, while also made from soybeans, is low-FODMAP. Guidance from a dietitian can be helpful for navigating this diet, but insurance coverage and medical referrals can be barriers to scheduling an appointment. As a result, some patients simply receive a list of low- and high-FODMAP foods.
Risks associated with not reintroducing some high-FODMAP foods
While avoiding high-FODMAP foods can be difficult, adding the carbohydrate groups back systematically to test tolerance can be even more challenging. Some people become hesitant to reintroduce items, especially if they have experienced significant symptom relief during the elimination phase. This increases the potential for nutritional risks. For example, it’s common for people avoiding dai