Several underlying mechanisms could be discussed in the pathophysiology of irritable bowel syndrome (IBS) as a multifactorial disease: low-grade inflammation, history of childhood infections, hypersensitivity and alteration in visceral perception, gastrointestinal dysmotility, changes in gut microflora, emotional and psychological triggers, increase in intestinal permeability and food intolerance are amongst suggested reasons for IBS development.1
It was in 1929 when Alvarez first used the term ‘irritability’ in connection with the small intestinal muscle and attributed this concept to altered contractions or motor activity2 as a possible pathophysiological basis of what we know today IBS. Almost a century has passed and we continue to apply the term, even though there are reasons to analyze its utility. We should ask ourselves, as Michael Camilleri3 did: Is the bowel really ‘irritable’? Does ‘irritable’ imply hypersensitivity?
The term ‘irritable’ is equivocal and does not inform the physician of the cause or mechanism of the disorder of function. Multiple studies show that there is visceral hypersensitivity (VH) in the vast majority of patients, or in other words, enhanced intestinal perception converting otherwise physiological stimuli into discomfort. It has been demonstrated that the gut mucosa of patients with IBS has significantly more nervous tissue and the associated mediators of nerve growth when compared with healthy controls, and this undoubtedly plays a dominant role in abdominal pain.4,5
The fact that VH plays a major role in the etiology of IBS symptoms becomes increasingly important and in this sense, studies are focusing on new treatments that are beginning to be used for IBS management.1
All of this should lead us to consider changing the term ‘irritable’, which is no longer useful, to ‘sensitive’. Thus, we would do well to talk about sensitive (or hypersensitive) bowel syndrome (SBS), which denotes the true importance of VH in its etiopathogenesis, in contrast to ‘irritable’, which comes from the Latin irritabilis, that is, prone to irritation, which means nothing in relation to the pathogenesis of the disorder.
I’m sure that Michael Camilleri will think as I do. I wish I could have discussed all this with Alvarez, too.
