A nutritionally balanced diet that is low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) for adults with irritable bowel syndrome (IBS).
Basis of the intervention
FODMAPs are fermentable, osmotically active, short-chain carbohydrates that are either not absorbed or only slowly absorbed in the small intestine. The unabsorbed carbohydrates, along with osmotically trapped water and electrolytes, enter the colon where they are rapidly fermented by bacteria to short-chain fatty acids and carbon dioxide, hydrogen and methane.
FODMAPs increase small intestinal water volume and colonic gas production, with secondary effects on small and large intestine motility. These factors may lead to symptoms of IBS, especially in those with visceral hypersensitivity and/or gastrointestinal motility abnormalities.
Although lactose intolerance may be associated with IBS, fructose malabsorption, where some ingested fructose reaches the colon, is a physiological occurrence.
Patients diagnosed with IBS.
Diagnosis of IBS
IBS is defined by the Rome III criteria as recurrent abdominal pain or discomfort for at least 3 days each month in the last 3 months in the absence of a pathologically based disorder. Pain and discomfort must be associated with at least two of:
- the abdominal pain/discomfort improves on defecation
- the onset is associated with a change in frequency of stool
- the onset is associated with a change in form (appearance) of stool.
For a diagnosis of IBS, the onset of symptoms must have occurred at least 6 months before the initial clinical presentation, in addition to fulfilling the criteria cited above.