Towards a better understanding of abdominal bloating and distension in functional gastrointestinal disorders

Abdominal bloating is an extremely common symptom affecting up to 96% of patients with functional gastrointestinal disorders and even 30% of the general population. To date bloating has often been viewed as being synonymous with an actual increase in abdominal girth, but recent evidence suggests that this is not necessarily the case. This review examines the relationship between the symptom of bloating and the physical sign of abdominal distension, as well as examining the epidemiology, pathophysiology and treatment options available for this debilitating aspect of the functional gastrointestinal disorders. Pathophysiological mechanisms explored include psychological factors, intestinal gas accumulation, fluid retention, food intolerance and malabsorption of sugars, weakness of abdominal musculature, and altered sensorimotor function. Treatment options are currently rather limited but include dietary changes, pharmacological approaches, probiotics and hypnotherapy.

IgG-mediated food intolerance in irritable bowel syndrome: a real phenomenon or an epiphenomenom?

Abnormal reactions to food probably contribute to the complex pathophysiology of irritable bowel syndrome, but the mechanisms involved remain unclear. Following the recent identification of subtle mucosal inflammation in at least some patients with the disorder, perhaps now is the time to revisit some of the immunological reactions to dietary antigens that, in the past, have been dismissed as irrelevant.

Diagnostic criteria for irritable bowel syndrome: utility and applicability in clinical practice

BACKGROUND/AIMS

Symptom-based criteria have been introduced to aid the diagnosis of irritable bowel syndrome (IBS). Although they have been widely adopted and have proved useful for research purposes by ensuring homogeneity of study populations, there is little information about their utility in routine clinical practice. It was the aim of this study to assess the applicability of the Manning, Rome I and Rome II criteria in the clinical setting and to ascertain how often hospital specialists and general practitioners (GPs) use them.

METHODS

Hundred secondary-care IBS patients were assessed for their conformity to these criteria. Forty-eight hospital specialists and 68 GPs were asked about their knowledge and utilization of these criteria.

RESULTS

Seventy-three percent of IBS patients met Rome II diagnostic criteria with 82 and 94% meeting Rome I and Manning, respectively. Approximately 80% of GPs had no knowledge of any of the specific criteria, and only 4% had ever used them. The majority of specialists had knowledge of the criteria, with 70% having used them.

CONCLUSION

The Rome II criteria are remarkably insensitive and if rigidly applied in the clinical situation would lead to much diagnostic uncertainty. The current lack of interest in them, especially amongst GPs, is unlikely to change unless they can be considerably improved.

The role of food intolerance in irritable bowel syndrome

Irritable bowel syndrome patients frequently believe that food intolerances are to blame for many of their symptoms, although not uncommonly this is caused by the nonspecific increase in gut motility that occurs with food ingestion. Nevertheless, dietary manipulation may result in substantial improvement in IBS symptomatology provided it is individualized to the particular patient. By further understanding the mechanisms involved in dietary intolerance, it should be possible to optimize the benefits of this approach to treatment.

Hypnotherapy in the treatment of irritable bowel syndrome

There is accumulating and compelling evidence that hypnotherapy is an effective treatment for irritable bowel syndrome. Recently, studies have shown that hypnotherapy has beneficial effects that are long lasting, with most patients maintaining improvement, and with decreased consultation and medication needs in the long term. The particular gut directed approach used, which is aimed at normalizing and controlling gut function, is also described. While the mechanisms of how hypnotherapy brings about its therapeutic effect are not fully known, changes in colonic motility and rectal sensitivity have been demonstrated, although changes in central processing and psychological effects may also play a role.

Suicidal ideation in patients with irritable bowel syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) traditionally is considered as more of a nuisance than having especially serious consequences. However, this is not the picture witnessed in tertiary care where we have encountered some tragic cases, prompting an assessment of suicidal ideation in such patients.

METHODS

One hundred follow-up, tertiary care IBS (tIBS) patients were compared with 100 secondary IBS (sIBS), 100 primary IBS (pIBS) care patients, and 100 patients with active inflammatory bowel disease (IBD). Patients were asked if they had either seriously contemplated or attempted suicide specifically because of their bowel problem as opposed to other issues. The hospital anxiety depression score was recorded, as were other clinical details on all patients.

RESULTS

A total of 38% of tIBS patients had contemplated suicide because of their symptoms compared with 16% and 4% in the sIBS and pIBS groups (tIBS vs. sIBS vs. pIBS, P = .002, P < .001). The figure for IBD was 15% (tIBS v. IBD, P < .001). Five tIBS and 1 IBD patient had attempted suicide for gastrointestinal reasons. Mean depression scores did not exceed threshold (10) in the sIBS group contemplating suicide (9.7), but were increased in the equivalent tIBS group (11.7). Hopelessness because of symptom severity, interference with life, and inadequacy of treatment were highlighted as crucial issues for all IBS patients.

CONCLUSIONS

IBS has the potential for a fatal outcome from suicide with depression not accounting for all the variance in suicidal ideation. Our observations emphasize the level of hopelessness felt by these patients and the need for improvement in the services provided to them.

Quality of life and illness costs in irritable bowel syndrome

Quality of life is reduced in patients with irritable bowel syndrome, and the costs for this disease are substantial to society. During a meeting in London, UK, the IBiS club reviewed the literature on these subjects. Drawbacks and advantages with existing instruments to assess quality of life and costs were discussed and the clinical and scientific relevance of the current knowledge was assessed. A summary from the meeting is presented in this paper.

Irritable bowel syndrome, chronic pelvic inflammatory disease and endometriosis: a comparison of symptomatology

BACKGROUND AND OBJECTIVES

Both irritable bowel syndrome and some gynaecological diseases can give rise to lower abdominal pain, which may result in diagnostic confusion. Disorders such as endometriosis and chronic pelvic inflammatory disease can be diagnosed definitively only by laparoscopy, which is seldom undertaken in the gastroenterological setting. It was the aim of this study to compare the symptomatology of irritable bowel syndrome with that of laparoscopically confirmed chronic pelvic inflammatory disease and endometriosis.

PATIENTS AND METHODS

A symptom questionnaire was administered to 50 women with irritable bowel syndrome and 51 gynaecological patients (30 patients with endometriosis, 21 patients with chronic pelvic inflammatory disease). As the symptoms of the two gynaecological conditions were so similar, the groups were combined for the purposes of comparison with irritable bowel syndrome.

RESULTS

Patients with irritable bowel syndrome suffered significantly more upper abdominal pain, colicky pain and exacerbation of pain by food or stress. They also experienced more disturbance of bowel habit, distension and nausea. In contrast, the only gynaecological features that were more common in the gynaecological patients were intermenstrual bleeding, premenstrual exacerbation of pain and forniceal tenderness.

CONCLUSION

The presence of gastrointestinal symptomatology, especially bowel dysfunction, in a woman with lower abdominal pain is suggestive of irritable bowel syndrome. However, the history may not be so helpful in detecting gynaecological disease.

Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial

BACKGROUND

Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies.

AIMS

To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food.

PATIENTS

A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies.

METHODS

Primary outcome measures were change in IBS symptom severity and global rating scores. Non-colonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model.

RESULTS

After 12 weeks, the true diet resulted in a 10% greater reduction in symptom score than the sham diet (mean difference 39 (95% confidence intervals (CI) 5-72); p = 0.024) with this value increasing to 26% in fully compliant patients (difference 98 (95% CI 52-144); p<0.001). Global rating also significantly improved in the true diet group as a whole (p = 0.048, NNT = 9) and even more in compliant patients (p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24% greater deterioration in symptoms in those on the true diet (difference 52 (95% CI 18-88); p = 0.003).

CONCLUSION

Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.

Psychological influences on the irritable bowel syndrome

Irritable bowel syndrome (IBS) is often considered as a purely psychosomatic condition. However, there is now good evidence that it is a multifactorial condition with a whole variety of influences leading to disease expression, of which psychological issues are only one. Nevertheless, addressing psychosocial problems forms an important part of the therapeutic approach to IBS. It is now known that ongoing social stress can make IBS refractory to treatment and there is increasingly firm data to support the notion that antidepressant pharmacotherapy and a variety of behavioural treatments, offer patients with more severe forms of the illness a chance of long-term improvement.

Technologies in the evaluation of irritable bowel syndrome

During a meeting in The Hague, The Netherlands, the IBiS Club evaluated the most important techniques that can be used in the investigation of irritable bowel syndrome, either in the context of scientific research or as a clinical diagnostic tool. In each of these, the relevance of findings made in irritable bowel syndrome was balanced against the applicability of the technique. The discussion of the group is summarized in this paper.

Gender and irritable bowel syndrome: the male connection

BACKGROUND/GOALS

Irritable bowel syndrome is more common in women; and this is generally considered to be caused by increased susceptibility. However, the opposite possibility that being male might actually protect from the disorder in some way, has largely been ignored. We have noticed that men with IBS seem to display less masculine and more feminine qualities and it was the purpose of this study to confirm or refute this clinical observation.

STUDY

Seventy consecutive male, secondary care outpatients fulfilling the Rome 1 criteria for irritable bowel syndrome and 70 controls completed a questionnaire to determine male and female-trait scores. In addition, all subjects were assessed using the hospital anxiety depression inventory.

RESULTS

A highly significant reduction in male-trait scores was observed in the irritable bowel syndrome patients compared with controls (-10.5[-15.7,-5.2] P < 0.001). There were no differences between the groups with respect to female-trait scores. The prevalence of homosexuality was no different between patients and controls.

CONCLUSION

Men with irritable bowel syndrome exhibit less male characteristics and it remains to be determined whether this is cause or effect. Whatever the explanation, this study adds another dimension to the role of gender in functional gastrointestinal disorders.

Inter-digestive and post-prandial antro-pyloro-duodenal motor activity in humans: effect of 5-hydroxytryptamine 1 receptor agonism

BACKGROUND

Little is known about the effect of 5-hydroxytryptamine 1 (5-HT(1)) receptor agonism on the co-ordinated motor activity of the gastric antrum, pylorus and duodenum under fasting and fed conditions.

AIM

To evaluate the effect of sumatriptan, a 5-HT(1) agonist, on fasting and fed antro-pyloro-duodenal motility.

METHODS

In study 1, antro-pyloro-duodenal motility was recorded for two phase IIIs of the migrating motor complex and then, following either a subcutaneous injection of sumatriptan 6 mg or saline control, for at least one additional phase III in 11 healthy volunteers (21-36 years). In study 2, the post-prandial motility was recorded for 3 h after either a subcutaneous injection of sumatriptan 6 mg or saline control in 10 healthy volunteers (18-36 years).

RESULTS

Sumatriptan prolonged the migrating motor complex cycle (P = 0.009) by increasing the duration of phase II (P = 0.02) but not phases I and III. Post-prandially, sumatriptan reduced the activity index (P = 0.017) by reducing the frequency of co-ordinated motor activity involving the antrum and/or the duodenum (P < 0.05).

CONCLUSION

5-HT(1) receptor agonism increases the periodicity of the migrating motor complex and reduces the occurrence of post-prandial co-ordinated motor activity involving the gastric antrum, pylorus and duodenum.

Cognitive change in patients undergoing hypnotherapy for irritable bowel syndrome

OBJECTIVE

Impaired quality of life and psychological distress are common in irritable bowel syndrome (IBS) and may be associated with unhelpful cognitions. Hypnotherapy (HT) is effective in improving both symptoms and quality of life in patients with IBS, and this study was designed to determine whether this improvement is reflected in cognitive change using a validated scale recently developed for use in such patients.

METHOD

A total of 78 IBS patients completed a validated symptom-scoring questionnaire, the Hospital Anxiety and Depression (HAD) Scale and the Cognitive Scale for Functional Bowel Disorders (FBDs), before and after 12 sessions of gut-focused HT.

RESULTS

HT resulted in improvement of symptoms, quality of life and scores for anxiety and depression (all P's<.001). IBS-related cognitions also improved, with reduction in the total cognitive score (TCS; P<.001) and all component themes related to bowel function (all P<.001). Cognitions were related to symptom severity because the most abnormal cognitive scores were observed in patients with the highest symptom scores (P<.001). Furthermore, a reduction in symptom score following treatment correlated with an improvement in the cognitive score (P<.001). Regression analysis confirmed that the cognitive score had independence from the other scores and did not serve solely as a proxy for symptom improvement.

CONCLUSION

This study shows that symptom improvement in IBS with HT is associated with cognitive change. It also represents an initial step in unravelling the many possible mechanisms by which treatments such as HT might bring about improvement.

Benefit-Risk Assessment of Tegaserod in Irritable Bowel Syndrome

Tegaserod is a new partial agonist of serotonin 5-HT4 receptors specifically developed for the treatment of nondiarrhoeal forms of irritable bowel syndrome (IBS). Among its various effects is the stimulation of the peristaltic reflex with its promotility action appearing to affect the whole length of the gastrointestinal tract. Tegaserod has been assessed in a number of international multicentre trials and its use leads to an improvement in abdominal pain and bowel dysfunction as well as global well-being, at the expense of remarkably few adverse effects. It is noteworthy that it also appears to improve bloating, a benefit that has not been previously reported for a medication used in IBS. The optimal dose is 6 mg twice daily and the advantage of tegaserod over placebo in different trials varies from 5-20% with the number needed to treat ranging from 5-15 depending on the time at which this effect is calculated during the course of a trial. Recent experience with other drugs acting on 5-HT receptors has focused attention on possible safety issues such as prolongation of the QTc interval on the electrocardiogram and ischaemic colitis. However, data from efficacy trials and studies specifically designed to address the safety of tegaserod have not revealed any evidence of cardiotoxicity or the potential for causing ischaemic colitis. Furthermore, investigation of possible interactions with other drugs such as warfarin or the oral contraceptive have not resulted in any prescribing restrictions. Inappropriate prescription of tegaserod to a subgroup of IBS patients for which the drug was not designed, does not appear to have any serious consequences. Most of the efficacy data on tegaserod has been accumulated in females, simply as a result of the failure to recruit adequate numbers of males or restriction of trials to females. There is therefore insufficient information to assess whether there might be any potential gender differences in responsiveness. For this reason, the drug is currently only licensed for use in females.

Tegaserod for the treatment of irritable bowel syndrome

BACKGROUND

IBS is a complex disorder that encompasses a wide profile of symptoms. Current drug treatments for irritable bowel syndrome (IBS) are of limited value. Many target specific symptoms only. Tegaserod, a 5HT(4) partial agonist, represents a novel mechanism of action in the treatment of IBS.

OBJECTIVES

The objective of this review was to evaluate the efficacy and tolerability of tegaserod for the treatment of IBS in adults and adolescents aged 12 years and above.

SEARCH STRATEGY

MEDLINE 1966-November 2002 and EMBASE 1980-November 2002 were searched. The text and key words used included "tegaserod", "HTF 919", "irritable bowel", and "colonic diseases, functional". The Cochrane Central Register of Controlled Trials, the Inflammatory Bowel Disease Review Group Specialized Trials Register, and Science Citation Index were also searched. Proceedings from the British Society of Gastroenterology Annual Meeting, and Digestive Disease Week (1998-2002) were hand searched. The manufacturer of tegaserod was contacted. Relevant articles were retrieved, and their reference lists were also reviewed.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing tegaserod with placebo, no treatment or any other intervention (pharmacological or non-pharmacological) in subjects aged 12 years and above with a diagnosis of IBS, focusing on clinical endpoints were considered for review.

DATA COLLECTION AND ANALYSIS

Study inclusion and exclusion, data extraction and quality assessment was undertaken by two reviewers independently. Meta-analysis was performed where study populations, designs, outcomes, and statistical reporting allowed combination of data in a valid way, using the summary statistic relative risk with 95% CI. Eight short-term placebo-controlled studies fulfilled our inclusion criteria. These were predominantly conducted in women. Seven studies evaluated the efficacy of tegaserod on global gastrointestinal (GI) symptoms in patients with constipation-predominant IBS (C-IBS). One small study evaluated safety in patients with diarrhoea-predominant IBS.

MAIN RESULTS

The relative risk (RR) of being a responder in terms of global relief of GI symptoms was significantly higher with tegaserod 12 mg (RR 1.19, 95% CI 1.09, 1.29) and tegaserod 4 mg (RR 1.15, 95% CI 1.02, 1.31) compared with placebo, with a number needed to treat (NNT) of 14 and 20 respectively. When all tegaserod doses were combined and compared with placebo (n=4040), the RR of being a responder was 1.17 (95% CI 1.08, 1.27), with a NNT of 17. Although the pooled results indicate statistically significant benefit with tegaserod, the a priori minimal clinically important differences set in two of the four pooled studies were not reached. Tegaserod did not significantly improve the patients' individual symptoms of abdominal pain and discomfort although bowel habit showed a statistically significant improvement with tegaserod 4 mg and there was a non-significant trend in favour of tegaserod 12 mg. When GI symptoms were assessed separately, those indicative of GI motility such as number of bowel movements and days without bowel movements were generally improved with tegaserod although the proportion of patients experiencing diarrhoea was significantly higher in the tegaserod 12 mg group compared with placebo (RR 2.75, 95% CI 1.90, 3.97), with a number needed to harm (NNH) of 20. Effects of tegaserod on GI symptoms such as bloating, stool consistency, and straining were not consistent across the studies.

REVIEWER'S CONCLUSIONS

Tegaserod appears to improve the overall symptomatology of IBS but there are currently few data on its effect on quality of life. In addition, more information is needed about its efficacy in men. It would also be of interest to know whether treatment with tegaserod leads either directly, or indirectly, to changes in visceral sensitivity or psychopathology, which are also considered important in the pathophysiology of this condition.

Long term benefits of hypnotherapy for irritable bowel syndrome

BACKGROUND AND AIMS

There is now good evidence from several sources that hypnotherapy can relieve the symptoms of irritable bowel syndrome in the short term. However, there is no long term data on its benefits and this information is essential before the technique can be widely recommended. This study aimed to answer this question.

PATIENTS AND METHODS

204 patients prospectively completed questionnaires scoring symptoms, quality of life, anxiety, and depression before, immediately after, and up to six years following hypnotherapy. All subjects also subjectively assessed the effects of hypnotherapy retrospectively in order to define their "responder status".

RESULTS

71% of patients initially responded to therapy. Of these, 81% maintained their improvement over time while the majority of the remaining 19% claimed that deterioration of symptoms had only been slight. With respect to symptom scores, all items at follow up were significantly improved on pre-hypnotherapy levels (p<0.001) and showed little change from post-hypnotherapy values. There were no significant differences in the symptom scores between patients assessed at 1, 2, 3, 4, or 5+ years following treatment. Quality of life and anxiety or depression scores were similarly still significantly improved at follow up (p<0.001) but did show some deterioration. Patients also reported a reduction in consultation rates and medication use following the completion of hypnotherapy.

CONCLUSION

This study demonstrates that the beneficial effects of hypnotherapy appear to last at least five years. Thus it is a viable therapeutic option for the treatment of irritable bowel syndrome.

Irritable bowel syndrome or endometriosis, or both?

Both irritable bowel syndrome and endometriosis are common conditions, although symptomatic gastrointestinal endometriosis is extremely rare. We report the case of a patient initially thought to have irritable bowel syndrome, in whom the diagnosis of endometriosis only became clear following a laparotomy for small bowel obstruction. This case highlights the need to question the diagnosis in patients with irritable bowel syndrome when there is any uncertainty, and also to appreciate that other pathology can arise, even when the diagnosis is secure.

Clinical trial guidelines for pharmacological treatment of irritable bowel syndrome

Appropriate guidelines for clinical trials in irritable bowel syndrome are needed because of the inadequacy of previously performed trials, the use of new and more adequate patient definition, new emerging pathophysiological models and the unique requirements related to the assessment of treatment outcome that, in the absence of a biological marker, can rely only on the evaluation of clinical manifestations. This consensus report highlights the following points. (a) A 4-week period is considered to be adequate to assess drug efficacy for the control of symptoms. (b) For the cyclic and non-life-threatening nature of the disease, a long-term study of 4-6 months or more of active treatment to establish efficacy is considered to be inappropriate in the large majority of patients. (c) In the initial assessment phase of drug efficacy, the withdrawal effect of treatment can be ascertained during a follow-up period prolonged for a sufficient time (4-8 weeks) after stopping treatment. Subsequent trials with proper withdrawal phase design and duration can then ascertain the drug post-treatment benefit. (d) Considering the intermittent clinical manifestations of irritable bowel syndrome, designing trials with on-demand or repeated cycles of treatment could be envisaged. However, the lack of a definition of what constitutes an exacerbation is a major obstacle to the design of such trials. In the absence of an established gold standard, appropriately justified novel trial designs are welcome. (e) Patients eligible for inclusion should comply with the Rome II diagnostic criteria for irritable bowel syndrome. (f) The main efficacy outcome of the treatment should be based on one primary end-point. (g) The primary efficacy end-point could combine, in a global assessment, the key symptoms (abdominal pain, abdominal discomfort, bowel alterations) of irritable bowel syndrome or rate any single symptom for drugs considered to target specific symptoms. (h) A 50% improvement in the primary efficacy end-point seems to be a reasonable definition of a responder.

New insights into the psychosocial aspects of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common condition varying in severity from trivial to incapacitating. The more severe cases are associated with poor quality of life, absenteeism from work, frequent consultation with medical professionals, and psychosocial distress. Historically the disorder was often considered as purely psychosomatic in origin, but we now know that this is a gross oversimplification. Gastrointestinal disorders are better understood using the biopsychosocial model, which emphasizes the importance of biologic and psychosocial factors. This article reviews the epidemiologic association of IBS with psychological and social stresses and explores how such stresses may influence consulting behavior and outcome. This review also describes physiologic mechanisms that may be involved in IBS and discusses the role of psychological therapies and psychotropic medication in the treatment of this condition.

Increased platelet depleted plasma 5-hydroxytryptamine concentration following meal ingestion in symptomatic female subjects with diarrhoea predominant irritable bowel syndrome

BACKGROUND

Meal ingestion is often associated with exacerbation of gastrointestinal symptoms in subjects with irritable bowel syndrome (IBS). Furthermore, recent preliminary data suggest that 5-hydroxytryptamine (5-HT) concentration in platelet poor plasma is elevated following meal ingestion in some subjects with diarrhoea predominant IBS (d-IBS) compared with healthy subjects, although it is not known whether this is related to postprandial symptomatology.

AIM

To expand on previous data by evaluating a larger number of subjects but also to assess plasma 5-hydroxyindole acetic acid (5-HIAA) concentrations, 5-HT turnover, platelet 5-HT stores, and any relationship to symptomatology.

METHODS

We assessed platelet depleted plasma 5-HT and 5-HIAA concentrations for two hours (60 minute intervals) under fasting conditions, and then for a further four hours (30 minute intervals) after a standard carbohydrate meal (457 kcal), together with fasting platelet 5-HT concentrations in 39 female subjects with d-IBS (aged 19-52 years; mean age 33) and 20 healthy female volunteers (aged 20-46 years, mean age 28). IBS symptomatology, in particular abdominal pain and bloating, and urgency to defecate were assessed throughout the study

RESULTS

When related to fasting levels, there was no statistically significant difference in postprandial plasma 5-HT concentrations between d-IBS and healthy subjects. However, when fasting levels were not taken into consideration, d-IBS subjects exhibited higher postprandial plasma 5-HT concentrations compared with healthy subjects (p=0.040). Furthermore, d-IBS subjects who exhibited postprandial symptomatology had higher levels of postprandial plasma 5-HT, whether assessed with respect to fasting baseline levels (p=0.069) or not (p=0.047), compared with d-IBS subjects who did not report postprandial symptomatology. This appeared to be associated with a concomitant increase in plasma 5-HIAA (p=0.161) but reduction in turnover (p=0.058). Lastly, d-IBS subjects had higher platelet concentrations of 5-HT than healthy subjects (p=0.009).

CONCLUSIONS

These data suggest that postprandial symptomatology may be associated with increased platelet depleted plasma 5-HT concentrations in female subjects with d-IBS. In addition, the presence of increased platelet stores of 5-HT may act as a useful marker for the diagnosis and management of d-IBS.

The prevalence, patterns and impact of irritable bowel syndrome: an international survey of 40,000 subjects

AIM

To determine the prevalence, symptom pattern and impact of the irritable bowel syndrome, across eight European countries, using a standardized methodology.

METHODS

A community survey of 41 984 individuals was performed using quota sampling and random digit telephone dialing to identify those with diagnosed irritable bowel syndrome or those meeting diagnostic criteria, followed by in-depth interviews.

RESULTS

The overall prevalence was 11.5% (6.2-12%); 9.6% had current symptoms, 4.8% had been formally diagnosed and a further 2.9%, 4.2% and 6.5% met the Rome II, Rome I or Manning criteria, respectively. Bowel habit classification varied by criteria: 63% had an 'alternating' bowel habit by Rome II vs. 21% by self-report. On average, 69% reported symptoms lasting for 1 h, twice daily, for 7 days a month. Irritable bowel syndrome sufferers reported more peptic ulcer (13% vs. 6%), reflux (21% vs. 7%) and appendectomy (17% vs. 11%), but not hysterectomy, cholecystectomy or bladder procedures. Ninety per cent had consulted in primary care and 17% in hospital; 69% had used medication. Irritable bowel syndrome substantially interfered with lifestyle and caused absenteeism.

CONCLUSIONS

Irritable bowel syndrome is common with major effects on lifestyle and health care. The majority of cases are undiagnosed and the prevalence varies strikingly between countries. Diagnostic criteria are associated with varying prevalences and bowel habit sub-types. This limits their utility in clinical practice and the transferability of research findings using them.