10 Things to Know About IBS and the Low FODMAP Diet

IBS and the Low FODMAP Diet.jpg

1.    IBS stands for Irritable Bowel Syndrome and is not to be confused with Inflammatory Bowel Disease (IBD), which includes Crohn’s disease and Ulcerative Colitis.

2.    It is one of the most common conditions seen by gastroenterologists and primary-care physicians, affecting between 7 and 15% of the population worldwide. In the US, the latest data show a prevalence of 8%. IBS is more common in women than in men and commonly diagnosed before the age of 50 years.

3.    IBS is characterized by a cluster of symptoms: abdominal pain, bloating, excessive flatulence, and altered bowel habits (diarrhea, constipation, or both) – symptoms that greatly affect the quality of life.

4.    There are a number of other diseases that have these same gastrointestinal symptoms, which makes IBS difficult to diagnose. It is important to have a diagnosis from a gastroenterologist before starting any dietary therapy as there is a risk to miss diagnosing diseases such as IBD, celiac disease, endometriosis or others.

5.    The cause of these symptoms is not well known and likely to be due to several mechanisms, with a complex interplay of physiological, psychological, and dietary factors. A number of therapies are available – drugs, dietary approaches, and psychological therapies – and it is thought that combining different tactics may optimize symptoms resolution. In recent years, there has been a major shift toward a more holistic approach with a focus on dietary therapies.

6.    The Low FODMAP diet was developed by researchers at Monash University in Australia as they gathered evidence from numerous studies that IBS symptoms improved after the restrictions of certain carbohydrates. In order to describe them, they created the term “FODMAP”:

  • Fermentable

  • Oligosaccharides

  • Disaccharides

  • Monosaccharides

  • Polyols

7.    These are sugars and fibers found in many healthy foods:

  • Sugars such as fructose (the main sugar in fruit) or lactose (the main sugar in milk)

  • Fibers (oligosaccharides) found in wheat, onions, beans and other foods

  • Sugar Alcohols (or Polyols) such as sorbitol and mannitol, found in some fruits, vegetables and sugar-free foods (gums, candy)

8.    In people with IBS, these carbohydrates are poorly absorbed or not absorbed at all. As such, they draw water and are fermented by bacteria in the gut, leading to excessive gas production, bloating, abdominal pain, and other symptoms after eating the foods that contain them.

9.    The Low FODMAP Diet is not a life-long diet and only needs to be followed until symptoms are resolved, typically 2-4 weeks. As it eliminates many nutritious foods, if followed long-term, this diet may lead to nutritional deficiencies.

10. The good news is that not all people are sensitive to all these foods and, through a systematic re-introduction under the guidance of an expert dietitian, each person can find out which foods are triggers for them. The ultimate goal is for IBS patients to liberalize their diet to include as many foods as possible while remaining mostly symptom-free.

Antonella Dewell