Diet Management

Research suggests that symptoms from irritable bowel syndrome (IBS) in one quarter of patients may be exacerbated by one or more dietary components, and dietary components may play a role in the causation of IBS in some patients.1 Several studies show a benefit in diets that eliminate or reduce certain foods that tend to exacerbate IBS symptoms, and most patients with IBS believe that diet plays a significant role in their symptoms.1,2

FODMAPs – Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols

A diet with increasing evidence of efficacy that is gaining traction among patients is a diet low in fermentable, poorly absorbed carbohydrates known as the FODMAP diet.2 The short-chain carbohydrates (sugars) have been shown to induce the IBS symptoms of diarrhea, bloating, abdominal pain, and gas due to their poor absorption, their ability to hold water in the intestinal tract, and rapid fermentation.3 Foods that are FODMAPs that are to be reduced or eliminated in the diet include:

  • Fructose (found in fruits, honey, high fructose corn syrup)
  • Lactose (found in dairy)
  • Fructans (found in wheat, garlic, onion)
  • Galactans (found in legumes such as beans, lentils, soybeans)
  • Polyols (found in sweeteners and stone fruits such as avocados, apricots, cherries, peaches, etc.)4

Gluten

Gluten is a protein found in grains such as wheat, barley and rye and is found in foods such as breads, pasta, and cereal.5 Gluten hypersensitivity, such as in celiac disease, can mimic the symptoms of IBS. The percentage of patients with IBS and celiac disease varies and may be as high as 32%. Multiple studies have shown that a gluten-free diet benefits patients with IBS, particularly patients with IBS with diarrhea (IBS-D).6

Caffeine

In a survey of more than 1,200 individuals with IBS, 41% reported they had made changes in their intake of caffeine. Coffee, with or without caffeine, is a known stimulant of intestinal movement and can cause diarrhea, however, it is unknown whether IBS makes patients more sensitive to caffeine. Several studies have shown that after experiencing improvement in IBS symptoms following an exclusion diet, coffee caused a recurrence of symptoms upon reintroduction in 14-33%, tea caused a recurrence in 18-28% of patients, and chocolate caused a recurrence in 6-28%. However, these percentages were within the range of placebo responses, and there are no reported randomized, controlled trials of a reduced coffee or caffeine diet in the treatment of IBS.1

Alcohol

Alcohol consumption is not significantly associated with IBS, but in a recent survey, up to 21% of individuals with IBS reported intolerance to alcoholic beverages and up to 12% limit or avoid them. After an exclusion diet, alcohol may caused a recurrence in symptoms in 9-14% of IBS patients, but there are no randomized, controlled trials of a reduced alcohol intake for the treatment of IBS.1

Artificial sweeteners

Several artificial sweeteners have been found to trigger IBS symptoms, in particular, the sugar alcohols, also known as polyols. Examples include sorbitol, mannitol, xylitol, lactitol, isomalt, erythritol and maltitol. These sweeteners are believed to ferment in the digestive tract, leading to the imbalance of bacteria in the gut and causing an exacerbation of IBS symptoms.2,4,7

High-gas foods

Some foods have been identified as high-gas foods – they cause the body to produce gas and cause more bloating, a common symptom experienced by IBS patients. The following foods are common high-gas foods that should be avoided or limited:

  • Beans
  • Broccoli
  • Brussels sprouts
  • Cabbage
  • Carbonated drinks
  • Cauliflower
  • Chewing gum
  • Fruits, such as apples, peaches, and pears
  • Hard candy
  • Lettuce
  • Milk and milk products
  • Onions
  • Sugar alcohols
  • Whole-grain foods 8

Dairy

Dairy products, such as milk, cheese, ice cream and yogurt, contain the sugar lactose. Lactose is not well digested or absorbed by a majority of adults,6 and there are conflicting studies as to whether patients with IBS have a greater risk of lactose intolerance.1 People with lactose intolerance experience many similar symptoms to IBS, including bloating, flatulence, abdominal pain, nausea and loose stools, following ingestion of dairy foods. In research studies, between 40-85% of IBS patients reported significant improvement in their IBS symptoms when following a restricted diet that eliminated dairy products.1

Additional Treatment Guidelines for IBS

Other dietary supplements that are commonly used in IBS treatment include the addition of probiotics and fiber to the diet. While dietary changes are an important tool in managing symptoms from IBS, patients may also benefit from medications, stress management, and alternative or complementary medicine.9
It is important to note that every patient responds to dietary changes, alternative or complementary treatment, and medications differently. It is often a trial and error process to determine the best treatment combination for each patient.

Written by: Emily Downward | Last reviewed: June 2016.
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