Determinants of healthcare-seeking behaviour among subjects with irritable bowel syndrome

BACKGROUND: Doctor visits for irritable bowel syndrome are associated with high medical costs. Predictors of medical consultation for irritable bowel syndrome remain poorly understood. AIM: To determine factors associated with healthcare seeking for irritable bowel syndrome. METHODS: Subjects from previous US population-based survey were contacted 2 years later. Those who continued to have irritable bowel syndrome were included. RESULTS: 49% of subjects sought medical care for abdominal symptoms in the past year. Healthcare seeking did not differ significantly between males and females, but more females received an irritable bowel syndrome diagnosis. Predictors of irritable bowel syndrome healthcare seeking differed by gender. In multivariate analysis, age > or = 55 years (OR = 2.8, 95% CI: 1.5-5.4), fear abdominal symptoms relates to serious illness (OR = 1.7, 95% CI: 0.95-3.1), decreased bowel movements (OR = 1.8, 95% CI: 0.98-3.2), dyspepsia (OR = 1.7, 95% CI: 0.94-3.2) and pelvic pain (OR = 2.3, 95% CI: 1.2-4.4) were associated with seeking care in females. Among males, being disabled (OR = 11.6, 95% CI: 2.4-56.1) and abdominal cramping (OR =4.3, 95% CI: 1.2-15.4) were associated with seeking care. Healthcare seekers had lower irritable bowel syndrome-related quality of life. Neither pain severity nor mental health status was associated with seeking care. CONCLUSION: Healthcare-seeking behaviour among irritable bowel syndrome patients was determined by presence of comorbidities and extent that irritable bowel syndrome affected quality of life, not physical symptoms or mental health status.     

Impact of functional gastrointestinal disorders on health-related quality of life: a population-based case-control study

BACKGROUND: The health-related quality of life is impaired in patients with functional gastrointestinal disorders seen in referral centres. AIM: To determine whether the health-related quality of life is impaired in subjects with functional disorders in the community and whether any differences can be explained by psychological co-morbidity. METHODS: In a population-based, nested, case-control study, subjects reporting symptoms of either dyspepsia or irritable bowel syndrome and healthy controls were interviewed and completed a battery of psychological measures plus a validated, generic, health-related quality of life measure (Medical Outcomes Study 36-item short form health survey, SF-36). The association between irritable bowel syndrome and dyspepsia and the physical and mental composite scores of SF-36 were assessed with and without adjustment for psychological state. RESULTS: One hundred and twelve cases (30 dyspepsia, 39 irritable bowel syndrome, 32 dyspepsia and irritable bowel syndrome and 11 gastrointestinal symptoms but not dyspepsia or irritable bowel syndrome) and 110 controls were enrolled. In the unadjusted linear regression models, irritable bowel syndrome (but not dyspepsia) was negatively associated with the physical composite score (P < 0.05); in an adjusted model, the association between the physical health-related quality of life and irritable bowel syndrome was explained by the Symptom Checklist-90 somatization score alone. In unadjusted models, irritable bowel syndrome and dyspepsia were each negatively associated with the mental composite score (P < 0.05). The association between the mental health-related quality of life and dyspepsia remained after adjusting for psychological covariates, but the association between this and irritable bowel syndrome was not significant after adjustment. CONCLUSIONS: In the community, health-related quality of life is impaired in subjects with irritable bowel syndrome and dyspepsia; however, much of this association can be explained by psychological factors.     

Predictive factors of irritable bowel syndrome improvement: 1-year prospective evaluation in 400 patients

BACKGROUND: The natural history of the irritable bowel syndrome is poorly understood. AIM: To assess the clinical course of the irritable bowel syndrome and the factors that might predict it. METHODS: An observational prospective study, involving 400 irritable bowel syndrome patients meeting Rome II criteria. Symptoms were recorded in a diary over four non-consecutive months (1, 4, 7 and 10). Demographic data, associated disorders, psychological status and health-related quality of life were obtained. RESULTS: At 1-year follow-up, half of the patients and half of their physicians considered irritable bowel syndrome to have improved, but improvement was minor. Diary data showed that, according to the type of symptom, improvement was small and quite different: diarrhoea in 19% of patients, abdominal pain frequency in 26%, constipation in 33% and abdominal pain intensity in 60%. Factors related to improvement at one year were: severe symptoms and poor health-related quality of life at first visit, irritable bowel syndrome-constipation, good improvement at 3 months, anxiety/depression, stress, symptoms related to meals and absence of comorbidity. By multivariate logistic regression, predictors were: severe basal symptoms and good improvement at 3 months (OR:CI 95%, 1.32:1.09-1.59 and 4.44:2.81-7.05). CONCLUSIONS: At 1-year follow-up, half the patients and their physicians considered the irritable bowel syndrome to have had some improvement but, symptom diaries demonstrated that improvement was small and heterogeneous. Severe basal symptoms and improvement at 3 months were related to better prognosis.     

Irritable bowel syndrome and other gastrointestinal disorders: evaluating self-medication in an Asian community setting

Background Gastrointestinal disorders frequently present symptoms which are often self-treated. Objective To record demographic profile of patients visiting community pharmacies for self-treatment with medications for gastrointestinal disorders, the number of these patients who fulfilled irritable bowel syndrome diagnostic criteria, and to judge the appropriateness of their treatment requests. Setting Singapore community pharmacies. Method The multicentre study was conducted using ROME III adapted criteria on adults above 18?years who have self-selected medicinal products for treatment of irritable bowel syndrome or gastrointestinal symptoms in the community pharmacy. Results Among those seeking self-medication, 36.8?% fulfilled criteria for irritable bowel syndrome, with irritable bowel syndrome-mixed (16.3?%) being the most prevalent subtype. For patients not fulfilling criteria for irritable bowel syndrome diagnosis, rates for other functional gastrointestinal disorders were constipation (20.5?%), dyspepsia (16.3?%), gastroesophageal reflux disease (12.1?%), diarrhoea (8.9?%), bloating (4.2?%), and heartburn (3.2?%). There were more females with gastrointestinal complaints. Overall, 21.6?% of the total participants had recently sought medical attention for their gastrointestinal complaint. 20?% of patients selected inappropriate medication for their gastrointestinal complaints, and the antacids class had the highest incidence of inappropriate medication use. Possible co-existing relationships were seen between gastroesophageal reflux disease with dyspepsia, irritable bowel syndrome with gastroesophageal reflux disease, irritable bowel syndrome with dyspepsia, and diarrhoea with constipation. Conclusion Patients who fulfilled criteria for irritable bowel syndrome had a high tendency to self-treat their gastrointestinal symptoms. Constipation complaints were also common. Around one in five patients self-medicated gastrointestinal symptoms inappropriately, with antacids being the most common.     

The treatment of irritable bowel syndrome

The efforts of clinical researchers, lay organizations and pharmaceutical companies have increased the public profile of irritable bowel syndrome and made it a respectable diagnosis. Diagnostic symptom criteria encourage a firm clinical diagnosis, which is the foundation of a logical management strategy. This begins with education. Reassurance that no structural disease threatens should be tempered with the reality that symptoms are likely to recur over many years. Patients expect diet and lifestyle advice, even if this is not specific to irritable bowel syndrome. Only a few of those with irritable bowel syndrome see doctors, and even fewer see specialists. Therefore, the treating physician should ascertain the reason for the visit, the patient's fears and the presence of any comorbid illness, such as depression, that might require treatment in its own right. No drug treatment is useful for all of the symptoms of irritable bowel syndrome, and many patients require no drug at all. If used, drugs should target the predominant symptom. Alosetron, a 5-HT3 antagonist, is effective in treating women with irritable bowel syndrome who also have diarrhoea. Tegaserod, a 5-HT4 agonist, is useful for women with irritable bowel syndrome who are constipated. Most patients with irritable bowel syndrome need psychological support. Reassurance, discussion and relaxation techniques can be provided by the family doctor. Difficult psychopathology may require referral to a mental health professional, and the gastroenterologist can settle diagnostic uncertainties. In all cases, successful treatment depends on a confident diagnosis and the strength of the doctor-patient relationship.     

Impact of advertisement and clinic populations in symptoms and perception of irritable bowel syndrome

BACKGROUND: This study assessed the impact of recruitment on irritable bowel syndrome clinical trials, by determining whether irritable bowel syndrome patients recruited from advertisement or a specialty clinic differ in clinical and physiologic measures. METHODS: We prospectively surveyed 657 irritable bowel syndrome patients who either: (i) were referred from a functional bowel disease clinic (52%); or (ii) responded to advertisement for clinical trials (48%), using questionnaires about bowel and psychological symptoms, and quality of life. In a subset of 42 irritable bowel syndrome patients (29 advertisement and 15 clinic patients), rectal discomfort thresholds were measured before and after repetitive sigmoid stimulation. RESULTS: While the advertisement population more commonly consulted primary care physicians, the clinic population more commonly consulted gastroenterologists. The clinic population reported more prevalent and severe abdominal pain, and higher psychological symptom scores, while the advertisement population had greater quality of life. In the visceral perception studies, both subgroups were hypersensitive to rectal distension. CONCLUSION: Compared to the clinic population, the advertisement population had less severe abdominal pain and psychological symptoms, better quality of life but similar visceral perception. The differences in clinical self-reports may have consequences for enrolment of these different patient populations into clinical trials.     

Clinical trial: short- and long-term benefit of relaxation training for irritable bowel syndrome

BACKGROUND: Psychotherapy is effective in treating irritable bowel syndrome, but the effect of relaxation training, a brief psychological group intervention, is not known. AIM: To determine the efficacy of relaxation training in a large cohort of irritable bowel syndrome patients. METHODS: Ninety-eight irritable bowel syndrome patients were included in this randomized controlled trial. Forty-six patients received standard medical care (CON) and 52 received four 90-min sessions of relaxation training in small groups in addition to standard medical care. Irritable bowel syndrome symptom severity, medical consumption and quality of life were assessed at baseline in patients and in 38 healthy controls and evaluated in patients at 3, 6 and 12 months after intervention. RESULTS: Irritable bowel syndrome symptom severity was significantly reduced in the relaxation training group compared to CON at 3, 6 and 12 months after treatment (time-by-treatment interaction, P = 0.002). The number needed to treat for long-term improvement was 5. Quality of life had improved (general health, P = 0.017; health change, P = 0.05). Frequency of doctor visits was reduced (P = 0.039). CONCLUSIONS: Relaxation training is a brief group intervention that significantly improves symptom severity, general health perception and medical consumption in irritable bowel syndrome patients immediately after, as well as 6 and 12 months after intervention.     

Psychophysical distress and alexithymic traits in chronic fatigue syndrome with and without comorbid depression

Patients with chronic fatigue syndrome (CFS) often report a comorbid depressive disorder. Comorbid depression may negatively influence the long-term outcome of CFS therefore it must be correctly diagnosed and treated. The aim of the present study is to provide a clinical and psychometric assessment of CFS patients with and without depressive features. A comparative analysis between 57 CFS subjects (CDC, 1994), 17 of whom with a comorbid depression, and 55 matched healthy volunteers was assessed to evaluate the presence of any psychophysical distress and alexithymic traits, by means of Symptom Checklist-90-R (SCL-90R) and Toronto Alexithymia Scale (TAS-20). The severity of fatigue was also assessed in all CFS patients using the Fatigue Impact Scale (FIS). With regard to psychiatric comorbidity, the SCL-90R scores showed higher levels of somatic complaints in CFS patients than in healthy subjects, whereas augmented depressive and obsessive-compulsive symptoms were observed only in the depressed CFS subgroup. When comparing the TAS-20 scores, we observed a selective impairment in the capacity to identify feelings and emotions, as measured by the Difficulty in Identifying Feelings subscale (DIF), non-depressed CFS patients showing an intermediate score between depressed CFS and healthy controls. Finally, in terms of FIS scores, a statistical trend versus a higher fatigue severity in depressed CFS patients, with respect to non-depressed ones, was observed. In conclusion, comorbid depression in CFS significantly increased the level of psychophysical distress and the severity of alexithymic traits. These findings suggest an urgent need to address and treat depressive disorders in the clinical care of CFS cases, to improve social functioning and quality of life in such patients.     

Anxiety but not depression determines health care-seeking behaviour in Chinese patients with dyspepsia and irritable bowel syndrome: a population-based study

AIMS: To study the prevalence of dyspepsia and irritable bowel syndrome and the effects of co-existing anxiety and depression on health care utilization by a population survey in Chinese. METHODS: Ethnic Chinese households were invited to participate in a telephone survey using a validated bowel symptom questionnaire and the hospital anxiety and depression scale. Gastrointestinal symptoms were classified as dyspepsia and irritable bowel syndrome according to the Rome I criteria and gastro-oesophageal reflux disease by the presence of weekly heartburn or acid regurgitation. The anxiety and depression scores were compared between patients who sought medical attention and those who did not, using multiple logistic regression analysis. RESULTS: One thousand, six hundred and forty-nine subjects completed the interview (response rate, 62%). The population prevalences of dyspepsia, irritable bowel syndrome and gastro-oesophageal reflux disease were 18.4%, 4.1% and 4.8%, respectively. Dyspepsia and irritable bowel syndrome were associated with anxiety, depression, medical consultation, sick leave and adverse effects on social life. The degree of anxiety was an independent factor associated with health care-seeking behaviour in both dyspeptics (P = 0.003) and irritable bowel syndrome patients (P = 0.036). CONCLUSIONS: Irritable bowel syndrome and dyspepsia are associated with anxiety, depression, significant social morbidity, health care utilization and days off work. Anxiety is an independent factor in determining health care utilization in patients with dyspepsia and irritable bowel syndrome.     

Gender difference on the symptoms, health-seeking behaviour, social impact and sleep quality in irritable bowel syndrome: a Rome II-based survey in an apparent healthy adult Chinese population in Taiwan

BACKGROUND: Little is known about the gender effect on irritable bowel syndrome in Asia. AIM: To assess the gender difference in Chinese subjects with irritable bowel syndrome meeting Rome II criteria. METHODS: Irritable bowel syndrome was identified from an apparently healthy adult population receiving a routine health maintenance program (n = 2018). RESULTS: Female gender is not a factor associated with irritable bowel syndrome or irritable bowel syndrome-related health care-seeking behaviour. Female irritable bowel syndrome subjects, irrespective of consulting behaviour for irritable bowel syndrome, are likely to have < 3 bowel movements/week, hard/lumpy stools and abdominal fullness/bloating (P < 0.05). Female irritable bowel syndrome subjects are prone to be absent from school/work with more days of absenteeism, irrespective of consultation status (P < 0.05). Only female irritable bowel syndrome consulters have more absenteeism for their irritable bowel syndrome-related symptoms, reporting more sleep disturbances than their male counterparts (P < 0.001). CONCLUSIONS: In an apparent healthy adult population in Taiwan, gender difference is present in Rome II defined Chinese subjects with irritable bowel syndrome as regards bowel symptoms, social impact and sleep quality. Female predominance was not found in irritable bowel syndrome subjects and irritable bowel syndrome-related health care-seeking behaviour in the current population. Both irritable bowel syndrome non-consulters and consulters have similar gender difference profiles in presenting symptoms, suggesting that bowel symptoms per se may not be the only factor leading to health care-seeking behaviour. The gender differences in sleep problems were observed solely in irritable bowel syndrome consulter.     

Calcium polycarbophil compared with placebo in irritable bowel syndrome

Calcium polycarbophil was compared with placebo in 23 patients with irritable bowel syndrome in a six-month, randomized double-blind crossover study. Patients received polycarbophil tablets at a dosage of 6 g/day (twelve 0.5-g tablets) or matching placebo tablets. At study end, among patients expressing a preference, 15 of 21 (71%) chose polycarbophil over placebo for relief of the symptoms of irritable bowel syndrome. Statistically significant differences favouring polycarbophil were found among the following patient subgroups: 15 (79%) of 19 with constipation; all six with alternating diarrhoea and constipation; 13 (87%) of 15 with bloating; and 11 (92%) of 12 with two or more symptoms. Polycarbophil was rated better than placebo in monthly global responses to therapy. Patient diary entries showed statistically significant improvement for ease of passage with polycarbophil. Polycarbophil was rated better than placebo for relief of nausea, pain, and bloating. The data suggest that calcium polycarbophil can benefit irritable bowel syndrome patients with constipation or alternating diarrhoea and constipation and may be particularly useful in patients with bloating as a major complaint.     

Stability of irritable bowel syndrome using a Rome II-based classification

BACKGROUND: As there is no biological marker for irritable bowel syndrome, a diagnosis is made using symptom-based criteria. AIM: To evaluate the stability of self-reported symptoms consistent with Rome II-based irritable bowel syndrome classification. METHODS: Irritable bowel syndrome subjects identified in a 2001 population-based study by modified Rome II criteria were re-contacted 2 years later. Data were collected via a web-based questionnaire. RESULTS: Of the 697 subjects, 30% remained in the same irritable bowel syndrome subtype in both surveys, 18.4% changed irritable bowel syndrome subtype and 52% no longer met the irritable bowel syndrome criteria at follow-up. Subjects continuing to meet the irritable bowel syndrome criteria were more likely to have been initially classified in the alternating irritable bowel syndrome subtype and had more psychological impairment and lower irritable bowel syndrome-related quality of life than subjects not fulfilling the irritable bowel syndrome criteria at follow-up. Lack of pain caused more subjects to fall out of the irritable bowel syndrome criteria than the absence of non-painful bowel symptoms. However, the majority of subjects that did not fulfill the pain component of the irritable bowel syndrome criteria continued to report abdominal pain of at least moderate severity. CONCLUSION: In a US population-based follow-up study using modified Rome II criteria, we found irritable bowel syndrome is episodic in nature and current classification is limited in capturing fluctuation of disease over time.     

Syuptomatology, quality of life and economic features of irritable bowel syndrome—the effect of hypnotherapy

Aims: The purposes of this study were to quantify the effects of severe irritable bowel syndrome on quality of life and economic functioning, and to assess the impact of hypnotherapy on these features. Methods: A validated quality of life questionnaire including questions on symptoms, employment and health seeking behaviour was administered to 25 patients treated with hypnotherapy (aged 25–55 years; four male) and to 25 control irritable bowel syndrome patients of comparable severity (aged 21–58 years; two male). Visual analogue scales were used and scores derived to assess the patients' symptoms and satisfaction with each aspect of life. Results: Patients treated with hypnotherapy reported less severe abdominal pain (P < 0.0001), bloating (P < 0.02). bowel habit (P < 0.0001), nausea (P < 0.05). flatulence (P < 0.05). urinary symptoms (P < 0.01), lethargy (P < 0.01), backache (P= 0.05) and dyspareunia (P= 0.05) compared with control patients. Quality of life, such as psychic well being (P < 0.0001), mood (P < 0.001), locus of control (P < 0.05), physical well being (P < 0.001) and work attitude (P < 0.001) were also favourably influenced by hypnotherapy. For those patients in employment, more of the controls were likely to take time off work (79% vs. 32%; p = 0.02) and visit their general practitioner (58% vs. 21%: P = 0.056) than those treated with hypnotherapy. Three of four hypnotherapy patients out of work prior to treatment resumed employment compared with none of the six in the control group. Conclusion: This study has shown that in addition to relieving the symptoms of irritable bowel syndrome, hypnotherapy profoundly improves the patients’quality of life and reduces absenteeism from work. It therefore appears that, despite being relatively expensive to provide, it could well be a good long-term investment.     

Serological testing for coeliac disease in patients with symptoms of irritable bowel syndrome: a cost-effectiveness analysis

BACKGROUND: Patients diagnosed with irritable bowel syndrome may have coeliac disease. AIM: To evaluate the cost-effectiveness of coeliac disease testing in suspected irritable bowel syndrome. METHODS: We used decision analysis to estimate the number of coeliac disease cases detected, quality-adjusted life-years gained, and costs resulting from testing suspected irritable bowel syndrome patients for tissue transglutaminase antibody or an antibody panel (tissue transglutaminase, gliadin, total immunoglobulin A). Positive tests prompted endoscopic biopsy. A gluten-free diet improved quality of life in coeliac disease. RESULTS: Assuming a coeliac disease prevalence of 3%, tissue transglutaminase detected 28 and the panel detected 29 of 30 coeliac disease cases among 1000 suspected irritable bowel syndrome patients. The cost/case detected was $4600 with tissue transglutaminase and $8800 with the panel. The cost/quality-adjusted life-year gained with tissue transglutaminase was $7400, and the incremental cost/quality-adjusted life-year gained for the panel vs. tissue transglutaminase was $287 000. Tissue transglutaminase cost under $100 000/quality-adjusted life-year gained at a coeliac disease prevalence >/=1.1%, assuming a modest utility gain of 0.005 with coeliac disease diagnosis. CONCLUSIONS: Testing for coeliac disease in patients with suspected irritable bowel syndrome is likely to be cost-effective even at a relatively low coeliac disease prevalence and with small improvements in quality of life with a gluten-free diet.     

Irritable bowel, smoking and oesophageal acid exposure: an insight into the nature of symptoms of gastro-oesophageal reflux

BACKGROUND: In gastro-oesophageal reflux disease, oesophageal acid exposure correlates with symptoms but explains only a small fraction of their variance. AIMS: To elucidate the effects of irritable bowel syndrome and smoking on gastro-oesophageal reflux disease symptoms and to clarify whether they modulate the relationship between oesophageal acid exposure and symptoms. METHODS: The relationship between oesophageal acid exposure, irritable bowel syndrome (Rome I criteria), smoking status and symptoms was investigated in patients with a normal gastroscopy who underwent a 24-h oesophageal pH monitoring. RESULTS: Of 256 patients with gastro-oesophageal reflux disease, 16% were smokers and 50% met the criteria for irritable bowel syndrome (irritable bowel syndrome+). The extent of oesophageal acid exposure was unrelated to smoking or irritable bowel syndrome status. Oesophageal acid exposure, irritable bowel syndrome status and current smoking independently predicted symptoms. Irritable bowel syndrome and smoking modulated the effect of oesophageal acid exposure on symptoms: oesophageal acid exposure was predictive of symptoms only in non-smokers. However, irritable bowel syndrome was a significant predictor of symptoms both in smokers and in non-smokers. Smoking was associated with symptoms only in irritable bowel syndrome+, while oesophageal acid exposure was associated with symptoms irrespective of irritable bowel syndrome status. CONCLUSIONS: In patients with non-erosive gastro-oesophageal reflux disease, smoking and irritable bowel syndrome independently predicted symptoms, without affecting the extent of oesophageal acid exposure. The relationship between oesophageal acid exposure and symptoms was affected significantly, and in opposite directions, by smoking and irritable bowel syndrome.     

Functional symptoms in inflammatory bowel disease and their potential influence in misclassification of clinical status

Background : Functional symptoms occur in inflammatory bowel disease probably more than in the general population. Existing disease indices rely heavily on symptoms that may be organic or functional. This may explain inconsistencies between recent therapeutic trials in inflammatory bowel disease. Clinically, misinterpretation can lead to over‐treatment of functional symptoms with potent agents, and to under‐treatment of inflammatory bowel disease when inflammatory features are more subtle. Aim : To assess functional symptoms in inflammatory bowel disease and to devise simple means of their evaluation. Methods : Patients with Crohn's disease, ulcerative colitis, and irritable bowel syndrome completed questionnaires, generating inflammatory bowel disease and irritable bowel syndrome indices. Data from outliers selected as exemplars were employed to create a new index. Results : One hundred and ninety patients completed questionnaires. Overall, Crohn's and irritable bowel syndrome patients had similar functional features. The new scoring system was based on the eight apparently discriminant symptoms. Prospective evaluation in a separate cohort of 180 inflammatory bowel disease patients yielded scores that are independent of established indices, inflammatory markers and psychometric scores. Conclusions : Patients with Crohn's report comparable rates of apparently functional symptoms to those with irritable bowel syndrome. A new score has been developed to help in their identification. This has the potential to guide therapeutic decisions and optimize future trial recruitment.     

Bran supplementation in the treatment of irritable bowel sgndrome

Background: Irritable bowel syndrome remains the commonest reason for referral to a gastroenterology clinic. Patients with irritable bowel syndrome are frequently advised to increase their intake of bran fibre, despite inconclusive experimental evidence of benefit. Methods: The effect of dietary supplementation with a bolus of bran fibre (12 g/day) was studied in a block-randomized, placebo-controlled, crossover study of 80 patients with irritable bowel syndrome referred to a District General Hospital outpatient clinic. Comparison of the benefits of bran and placebo was based upon personal assessment of individual and overall symptom profiles, determined from a simple daily symptom score and post-treatment interview. Results: Overall symptomatic improvement was reported with bran by 52% and with placebo by 54% of patients. Bran supplementation was no more effective than placebo in improving individual symptoms of irritable bowel syndrome, and for wind-related symptoms it was significantly less effective (P < 0.001). Conclusion: Dietary supplementation with bran is of no value in the treatment of patients with irritable bowel syndrome referred to a hospital clinic.