Irritable bowel syndrome
Robin C. Spiller
Wolfson Digestive Diseases Centre, University Hospital, Nottingham, NG7 2UH, UK
Irritable bowel syndrome (IBS) is one of the most common ‘functional’ gastrointestinal disorders accounting for 3% of all primary care consultations, with a strong female predominance. Although most of the literature comes from Westernindustrialized societies, when it has been looked for, this disorder appears to be equally common in the Third World. It is characterized by chronic abdominal pain or discomfort associated with disordered bowel habit and visceral hypersensitivity. Anxiety and somatization are more common in IBS than in the general population and may encourage consultation; however, they correlate poorly withsymptoms. Bacterial gastroenteritis may be followed by the development of IBS in 5–10% of patients, depending on the severity of initial illness and prior anxiety or depression. The Rome criteria allow reliable diagnosis provided that there are no ‘alarm’ features which mandate further investigation. Microscopic colitis and bile salt malabsorption can easily be mistaken for IBS, as can chronicinfestations or infections which should be considered, while recognizing that these are extremely uncommon in westernized societies. Some patients respond to exclusion diets as lactose and wheat intolerance are common. Others with prominent anxiety and/or depression respond to psychotherapy or antidepressants. Diarrhoeal symptoms respond to loperamide and 5HT3 receptor antagonists, while constipationresponds to 5HT4 agonists. Antispasmodics may have limited benefit in treating pain. Low-dose tricyclic antidepressants are also helpful in alleviating pain and anxiety, even in those without obvious psychiatric disorders. If diagnostic criteria are met, then once diagnosed, new diagnoses rarely appear.
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Accepted:January 5, 2005 Correspondence to: Professor Robin C. Spiller, Wolfson Digestive Diseases Centre, University Hospital, Nottingham, NG7 2UH, UK. E-mail: robin.spiller@nottingham. ac.uk
As ideas about the cause of irritable bowel syndrome (IBS) have changed over the years, so its name has varied from ‘nervous colitis’ to ‘mucous colitis‘or ‘spastic colon’, to name but a few. IBS is the mostcommon of the ‘functional gastrointestinal disorders’, so-called because it was believed that most of the symptoms originated in the central nervous system. A more sophisticated analysis shows that patients with IBS have disorders both peripherally in the gut and centrally in the brain, and symptoms arise because of an interaction between the two. At present,
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British Medical Bulletin 2004; 72: 15–29 DOI: 10.1093/bmb/ldh039
Robin C. Spiller
Table 1 Rome II Diagnostic Criteria for IBS1
At least 12 weeks or more, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain thathas two out of three features: 1. Relieved with defecation and/or 2. Onset associated with a change in frequency of stool and/or 3. Onset associated with a change in form/appearance of stool
in the absence of objective markers, the diagnosis is established by means of symptom-based criteria. Over the last 15 years these have been systematized by a number of working committees who haveattempted to generate criteria with the aim of facilitating comparison between various treatments and investigations carried out throughout the world (see http://www.romecriteria.org/rome12biblio.html). The current Rome II criteria are shown in Table 1. These criteria are constantly evolving and a new set of definitions (the Rome III criteria) is due to be published in 2006.