Editor,—The irritable bowel syndrome (IBS) is the commonest gastrointestinal disorder encountered by primary care physicians and a number of treatments, both pharmacological and psychological have been advocated. Individual and group psychotherapy, hypnotherapy and behaviour therapy have been shown to produce improvement. Pharmacological agents reported to be effective include antispasmodics, bulking agents, dopamine antagonists, carminatives, opioids, anticholinergics, and antidepressants.¹ Most patients respond to a combination of antispasmodics, bulking agents, a high fibre diet, and explanation coupled with reassurance.2

A comprehensive Medline search for papers on treatment resistant IBS failed to identify a single study which provided a satisfactory definition of this condition. IBS was considered refractory or intractable if patients had “not responded to any therapy”,3 “not responded to standard medical treatment”4 or had “no improvement from conventional medical treatment”.5

It seems that the terms refractory/intractable have been used rather loosely and what constitutes standard or conventional medical treatment is not clear. Moreover, if future studies consider IBS to be refractory as soon as pharmacological treatment fails, they would be ignoring the evidence supporting psychological therapies.

It is therefore proposed that IBS be considered “treatment resistant” if:

• symptoms are present for more than 12 months;

• the patient has received adequate explanation and reassurance for his/her symptoms;

• appropriate dietary interventions have occurred, including the institution of a high fibre diet when indicated;

• absence of response to an adequate dose of at least one pharmacological agent tried for a minimum of six weeks;

• absence of response to a minimum of six sessions of psychological treatment.

There is no consensus on what constitutes response, but one would expect global improvement and at least some specific measures to show significant changes. A 50% reduction in the predominant or target symptom (abdominal pain/abdominal distension/abnormal bowel habit) along with a similar improvement in subjective well being could be a clinically useful index of outcome.