The Low FODMAP Diet Approach: Dietary Triggers for IBS Symptoms
Irritable bowel syndrome (IBS) affects up to one in five Americans. It is a condition that is characterized by gut symptoms including abdominal pain, intestinal gas/wind, bloating, and changed bowel habit (ranging from diarrhea to constipation). Symptoms can often be debilitating and lead to a reduced quality of life.
A wide range of therapies have been used to control IBS symptoms including various medications, bulking agents and laxatives, and a myriad of lifestyle changes. Most individuals with IBS believe that their symptoms are related to the consumption of certain foods, but advice in this area has been conflicting and confusing and offered little relief for IBS sufferers.
An Australian research team has developed a new dietary management approach – the Low FODMAP diet – to control symptoms associated with IBS. In Australia, the low FODMAP diet is increasingly being accepted as the primary management strategy for IBS, recently adopted by their National Therapeutic Guidelines.
Understanding the FODMAP Concept
Carbohydrates can be present in different forms in foods, varying from long-chain carbohydrates (e.g. starch) to simple sugars (e.g. glucose) that are well-digested and absorbed to produce energy. Fiber and resistant starch are long-chain carbohydrates resistant to digestion and are important for stool formation and normal bowel function.
The Australian group has produced strong evidence that a group of short-chain carbohydrates, named FODMAPs (Fermentable Oligo-saccharides, Di-saccharides, Mono-saccharides And Polyols) are problematic for those with IBS. These short-chain carbohydrates are poorly absorbed in the small intestine and rapidly fermented by bacteria in the gut. The production of gas by these bacteria is a major contributor to symptoms.
A pilot study first observed that three out of four patients with IBS responded symptomatically to restriction of FODMAP intake. Subsequently, several high-quality clinical studies have further confirmed that improvement is due to the reduction in FODMAP intake.
Application of the low FODMAP diet is not only limited to IBS. It has also been shown to improve gut symptoms in more than 50% of patients with inflammatory bowel disease who are experiencing ongoing gut symptoms despite having inactive disease. In patients without a colon, the issue of frequent loose stool production was also reduced significantly.
The low FODMAP diet can be tailored to meet an individual’s lifestyle and preferences. Following the low FODMAP approach does not cure IBS, but allows successful drug-free management of symptoms through diet in many patients.