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Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder with no known organic cause. 5-10% of the population are affected, with sufferers being predominantly female with a peak incidence in the third or fourth decade of life. The average practice will have up to 100 such patients registered with them.
It is a symptom-based diagnosis characterised by chronic abdominal pain, bloating, wind and alteration of bowel habit. There may also be urgency of bowel movements, a feeling of incomplete evacuation (tenesmus), abdominal distension or upper GI symptoms such as nausea. In some cases, the symptoms are relieved by bowel movements. Pain may predominate.
The onset of IBS is more likely to occur after an infection or a stressful life event, but varies little with age.
Consider the following in your differential diagnosis:
In IBS, routine clinical tests must all be normal, although the bowels may be more sensitive to certain stimuli such as balloon insufflation testing.
If patients conform to the IBS diagnostic criteria above, the following interventions should be trialled (see details under ‘GP Management’):
Patients who do not respond to these may be considered to have ‘refractory IBS’. These patients may benefit from referral to the Refractory IBS Service, after faecal calprotectin screening (patients aged <45 years), or if previous investigation within the last 5 years has demonstrated no structural cause for symptoms, and there have been no change in symptoms since in patients over the age of 45 years.
Patients who do not respond to the above interventions may be considered to have ‘refractory IBS’. These patients may benefit from referral to the Refractory IBS Service, after faecal calprotectin screening (see above).
Please use the Refractory IBS Service Referral Form.
NICE DG11 (2013): “Many people with irritable bowel syndrome have unnecessary invasive hospital investigations before their condition is diagnosed. Using faecal calprotectin testing will mean most people with irritable bowel syndrome will be diagnosed without the need for these investigations.”
Patients with IBS are frequently over-investigated. The low FODMAP diet can be highly successful in treating these patients. Non-responders may then need further investigation.
The Refractory IBS Service run by GHFT is a complete service for patients considered by their GP to have IBS but have failed to respond to appropriate primary care management, as outlined in this guidance. The clinic will assess these patients, manage them and further investigate them if it is indicated.
IBS sufferers who do not respond to usual management are also those patients who may end up being extensively investigated with colonoscopy and other tests, with some risk and with little benefit or relief of their symptoms.
Recent research has shown that a high proportion of such patients may respond well to a Low FODMAP diet. This diet is low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). These substances increase the delivery of readily fermentable substrates and water to the distal small intestine and the colon. This results in increased gas production which in turn produces luminal distension and pain. Reducing FODMAPs in these patient’s diets may significantly improve functional gastrointestinal symptoms.
Refractory IBS Internal Clinic Pathway