Irritable bowel syndrome prevalence varies enormously depending on the employed diagnostic criteria: comparison of Rome II versus previous criteria in a general population.

BACKGROUND: Irritable bowel syndrome (IBS) prevalence estimates are essential for measuring the importance of the problem and the burden of the illness. However, IBS diagnosis is based on clinical criteria which have changed over time. The aim of this study was to assess how the use of different diagnostic criteria influences estimated IBS prevalence and, in particular, to compare how this prevalence varies using the new Rome II criteria and previous diagnostic criteria. METHODS: An epidemiological survey was conducted in the general population using personal interviews in a home setting. Two thousand individuals stratified by gender, age, social class and geographic location were randomly selected from the general population of Spain. Participants were classified as 'potential IBS subjects' (n = 281) or 'non-potential IBS subjects' (n = 1719) as a result of their response to a screening question regarding the presence of abdominal pain, constipation or diarrhoea. Thus, we estimated IBS prevalence according to the following diagnostic criteria: Manning, Rome I, Rome II, Drossman, Talley and Kay & Jorgensen. RESULTS: Prevalences of IBS according to the Manning and Rome I criteria were 10.3% and 12.1%, respectively. These were higher than the prevalences obtained with the other criteria used, which varied from 2.1% to 4.9%. IBS was more prevalent in females than males irrespective of the criteria used (the female:male ratio ranged from 2.33 to 4.33). Subjects who fulfilled the Rome II, Drossman, Talley or Kay & Jorgensen criteria also fulfilled the Rome I and Manning criteria. However, between 44% and 80% of subjects who fulfilled the Rome I or Manning criteria did not fulfil the more stringent diagnostic criteria. CONCLUSIONS: The prevalence of IBS varies enormously depending on the diagnostic criteria employed. Criteria based on the frequency of symptoms, such as the Rome II criteria, produce much lower prevalence values compared to criteria based solely on the presence of symptoms. In fact, more than two-thirds of subjects who fulfilled the Rome I criteria would not have been diagnosed with IBS if Rome II criteria had been employed.     

Irritable Bowel Syndrome Prevalence Varies Enormously Depending on the Employed Diagnostic Criteria: Comparison of Rome II Versus Previous Criteria in a General Population

Background: Irritable bowel syndrome (IBS) prevalence estimates are essential for measuring the importance of the problem and the burden of the illness. However, IBS diagnosis is based on clinical criteria which have changed over time. The aim of this study was to assess how the use of different diagnostic criteria influences estimated IBS prevalence and, in particular, to compare how this prevalence varies using the new Rome II criteria and previous diagnostic criteria. Methods: An epidemiological survey was conducted in the general population using personal interviews in a home setting. Two thousand individuals stratified by gender, age, social class and geographic location were randomly selected from the general population of Spain. Participants were classified as 'potential IBS subjects' ( n = 281) or 'non-potential IBS subjects' ( n = 1719) as a result of their response to a screening question regarding the presence of abdominal pain, constipation or diarrhoea. Thus, we estimated IBS prevalence according to the following diagnostic criteria: Manning, Rome I, Rome II, Drossman, Talley and Kay & Jorgensen. Results: Prevalences of IBS according to the Manning and Rome I criteria were 10.3% and 12.1%, respectively. These were higher than the prevalences obtained with the other criteria used, which varied from 2.1% to 4.9%. IBS was more prevalent in females than males irrespective of the criteria used (the female:male ratio ranged from 2.33 to 4.33). Subjects who fulfilled the Rome II, Drossman, Talley or Kay & Jorgensen criteria also fulfilled the Rome I and Manning criteria. However, between 44% and 80% of subjects who fulfilled the Rome I or Manning criteria did not fulfil the more stringent diagnostic criteria. Conclusions: The prevalence of IBS varies enormously depending on the diagnostic criteria employed. Criteria based on the frequency of symptoms, such as the Rome II criteria, produce much lower prevalence values compared to criteria based solely on the presence of symptoms. In fact, more than two-thirds of subjects who fulfilled the Rome I criteria would not have been diagnosed with IBS if Rome II criteria had been employed.     

Comorbidity and use of health-care services among irritable bowel syndrome sufferers

OBJECTIVE: Patients suffering from irritable bowel syndrome (IBS) have more somatic and psychiatric comorbidity and use more health-care services for comorbid conditions than do other patients. Little is known about the frequency of comorbid symptoms among IBS sufferers in the general population and their influence on use of health-care facilities. The objective of this study was to compare the frequency of somatic and psychiatric symptoms between IBS sufferers and controls in the general population, and to study how comorbidity rates are distributed among consulters and non-consulters and how they predict the use of health care-services. MATERIAL AND METHODS: By means of a questionnaire sent to 5000 randomly selected adults IBS was identified according to the Rome II criteria. The questionnaire also covered upper GI symptoms, non-GI somatic symptoms, depression and anxiety. A logistic regression analysis with 26 variables was carried out to determine the independent predictors of health-care seeking for GI and non-GI complaints. RESULTS: The response rate was 73% and prevalence of IBS 5.1% (95% CI 4.4-5.8%). Dyspeptic symptoms, somatic extra-GI symptoms and psychiatric symptoms were reported by 45%, 69% and 51% of IBS sufferers, respectively, and 6%, 35% and 27%, of controls, respectively. Visiting a physician because of GI complaints was associated with disturbing abdominal symptoms, but not with depression or anxiety. Of the present GI conditions, only dyspeptic symptoms were associated with an increased consultation rate also for non-GI complaints. CONCLUSIONS: In the general population, both IBS consulters and non-consulters demonstrate high rates of comorbidity. Seeking health care for abdominal complaints is associated with abdominal symptoms rather than psychiatric comorbidity.     

Prevalence of irritable bowel syndrome in young adult Malaysians: a survey among medical students

BACKGROUND AND AIMS: Irritable bowel syndrome (IBS) is a common functional bowel disease in the West. Information on the prevalence of IBS in the Asian population is relatively scanty. The aims of the present study were to determine the prevalence of IBS and to assess the symptom subgroups based on the predominant bowel habit in a young adult population of Asian origin. METHODS: Basic demographic data and symptoms of IBS using the Rome I criteria were sought using a questionnaire administered to all apparently healthy students in a medical school. Other questions asked related to alcohol intake, smoking, chili consumption, dietary fiber intake, and to psychological and psychosomatic symptoms of anxiety, depression, insomnia, headache, and backache. The health-care seeking behavior of the subjects was also analyzed. RESULTS: Of the 610 questionnaires administered, 533 complete responses were received (response rate of 87.4%). The responders comprised 229 men (43.0%) and 304 (57.0%) women with a mean age of 22 +/- 1.8 years. The ethnic distribution was Malays 278 (52.2%), Chinese 179 (33.6%), Indians 46 (8.6%), and others 30 (5.6%). Eighty-four (15.8%) reported symptoms consistent with the diagnosis of IBS, predominantly women. Sixty-five (77.4%) and six (7.1%) were of the constipation-predominant and diarrhea-predominant IBS subgroups, respectively. Thirteen (15.5%) subjects fell into the non-specific IBS subgroup. The self-reported psychological and psychosomatic symptoms of anxiety (P = 0.02), depression (P = 0.002), insomnia (P = 0.006), headache (P = 0.04), and backache (P = 0.006) were encountered more frequently in the subjects with IBS. Only 13.1% of the IBS group had consulted their health-care practitioner, and 20.2% reported self-medication. CONCLUSIONS: Symptoms supportive of the diagnosis of IBS were common among young Malaysians, with a prevalence rate of 15.8%. There were significantly more women with IBS than men. Within the IBS population, the majority (77.4%) was of the constipation-predominant IBS subgroup. A significantly higher prevalence of psychological and psychosomatic symptoms was found in individuals with IBS. Only a minority sought medical advice for their symptoms.     

Rome I criteria are more sensitive than Rome II for diagnosis of irritable bowel syndrome in Indian patients.

AIM: To assess the utility and efficacy of Rome I and Rome II criteria for the diagnosis of irritable bowel syndrome (IBS) in India. METHODS: Patients referred with a diagnosis of IBS by general practitioners answered a questionnaire about clinical features, including those listed in the Rome I and Rome II criteria. All patients underwent investigations to determine the cause of their symptoms. Sensitivity, positive predictive value and percent agreement of final diagnosis with Rome I and II criteria were calculated. RESULTS: Among 138 patients studied, 6 patients had organic disease . Amongst 132 patients with functional bowel disease, Rome I criteria diagnosed more patients as IBS than Rome II criteria (110 [83.3%] vs. 41 [31.1%]); 36 patients fulfilled both the criteria. Of the patients positive by Rome I, 32.7% fulfilled Rome II criteria, and of those diagnosed by Rome II criteria, 87.8% fulfilled Rome I criteria. Seventeen patients did not fulfill either Rome I or Rome II criteria, and were classified as functional abdominal bloating, functional diarrhea or functional constipation. CONCLUSION: Rome I criteria are more sensitive than Rome II criteria for the diagnosis of IBS in the Indian population.     

Prevalence of Irritable Bowel Syndrome and Depression in Fibromyalgia

The purpose of this study was to determine the point prevalence of depressive symptoms, using the PRIME-MD questionnaire, and irritable bowel syndrome (IBS), while comparing the Rome II to the Rome I criteria, in patients with fibromyalgia (FM) and rheumatologic controls in an outpatient setting. The prevalence of IBS in FM patients (n = 105) was 63% by Rome I and 81% by Rome II criteria. The prevalence of IBS in controls (n = 62) was 15% by Rome I and 24% by Rome II criteria (FM vs. control; P < 0.001). Depressive symptoms were met in 40% of FM patients and 8% of controls (P < 0.001). The coexistence of IBS and depressive symptoms in the FM patients was 31% (Rome I) and 34% (Rome II). The prevalence of IBS and depressive symptoms was higher in FM patients compared to the control population. Identification of IBS and depressive symptoms in FM patients might enable clinicians to better meet the needs of this patient population. The views expressed in this article are those of the authors and do not reflect the official policy or practice of the Department of the Navy, Department of Defense, or the United States Government. This research was performed at outpatient private rheumatology clinics. No financial support was received for the research     

Utility of the Rome I and Rome II criteria for irritable bowel syndrome in U.S. women

OBJECTIVES: Using interview data from a large, community-based sample of American women, we assessed the lifetime prevalence of irritable bowel syndrome (IBS) using questions consistent with the Rome II criteria, determined the sensitivity of Rome I and II in women diagnosed with IBS by their community physician, and identified whether there are differences in the patients identified by Rome I versus II. METHODS: A geographically diverse national probability sample of women diagnosed with IBS was identified and interviewed by telephone screening of a national, random digit dialing sample of households. A parallel national survey of adult females was conducted to determine the lifetime prevalence of IBS in U.S. women. Screening and interviews were conducted by experienced, female interviewers. IBS was defined by variations on the Rome I/II criteria. RESULTS: In the national community sample, lifetime IBS prevalence was 5.4% using Rome II. Full interviews were completed in 1,014 IBS patients. In the IBS sample, Rome I was significantly more sensitive than Rome II (84% vs 49%, p < 0.001). There was 47% agreement between Rome I and II. Of patients with IBS by Rome I, 58% met Rome II. Only 17.7% did not meet either Rome I or II. CONCLUSIONS: Rome I was more sensitive than Rome II in this community sample of female IBS patients. Rome I/II do not necessarily identify the same IBS patients. These findings have important implications for clinical research in IBS patients and raise questions about whether the Rome II criteria are sensitive enough to be useful in clinical practice.     

Functional Bowel Disorders in Iranian Population using Rome III Criteria

Background/Aim:

To study the prevalence and risk factors of functional bowel disorders (FBD) in Iranian community using Rome III criteria.

Materials and Methods:

This study was a cross-sectional household survey conducted from May 2006 to December 2007 in Tehran province, Iran, including 18,180 participants who were selected randomly and interviewed face-to-face by a validated questionnaire based on Rome III criteria.

Results:

In all, 1.1% met the Rome III criteria for irritable bowel syndrome (IBS), 2.4% for functional constipation (FC), and 10.9% of the participants had any type of FBD. Among participants with functional dyspepsia, 83.8% had FBD; the majority cases were unspecified functional bowel disorder (U-FBD). Of the subjects fulfilling the IBS criteria, IBS with constipation (52%) was the most frequent subtype. In the multivariate analysis, women had a higher risk of any FBDs than men, except for functional diarrhea (FD). The prevalence of FBD, FC and FD increased and IBS decreased with increasing age. Marital status was only associated with a decrease in the risk of FBD and FD, respectively. IBS subtypes compared with FC and FD. There was no significant difference between FC and IBS with constipation (IBS-C), except for self-reported constipation; while, IBS with diarrhea (IBS-D) had more symptoms than FD.

Conclusion:

This study revealed a low rate of FBDs among the urban population of Tehran province. The ROME III criteria itself, and the problems with interpretation of the data collection tool may have contributed in underestimating the prevalence of FBD. In addition the reliability of recall over 6 months in Rome III criteria is questionable for our population.     

Increased prevalence of irritable bowel syndrome in patients with gastroesophageal reflux

GOALS: To determine the prevalence of irritable bowel syndrome (IBS) in subjects with gastroesophageal reflux disease (GERD) compared with non-GERD controls. STUDY: Two hundred subjects were identified from a list of Cedars-Sinai Medical Foundation patients and gastroenterology motility practice subjects with and without a potential diagnosis of GERD. All subjects were then evaluated independently by two blinded physicians who were asked to identify subjects with GERD based on taking a history (gold standard). A follow-up questionnaire was later mailed to patients. This questionnaire included Rome I criteria for IBS. The prevalence of IBS was compared between GERD and non-GERD subjects. Finally, to further strengthen the method, a retrospective review of all subjects' charts was conducted to identify patients who had had 24-hour pH tests, and the prevalence of IBS was determined in this subgroup. RESULTS: Of the 200 subjects, 90 (45%) patients returned the questionnaire. After excluding subjects with IBD and incomplete questionnaires, there were 84 subjects (35 with GERD) included in the analysis. Of the 35 GERD subjects, 25 (71%) were Rome I criteria positive for IBS, whereas only 17 of the 49 (35%) non-GERD subjects had IBS (odds ratio = 54.7, CI = 1.7-13.5, p < 0.01). In 11 of the GERD subjects a 24-hour pH study was available and confirmed GERD. Of these 11 subjects, 7 (64%) met Rome I criteria for IBS. CONCLUSION: There is a higher prevalence of IBS in subjects with GERD compared with subjects without GERD.     

Irritable bowel syndrome according to varying diagnostic criteria: are the new Rome II criteria unnecessarily restrictive for research and practice?

OBJECTIVES: It has been suggested that the variation in the prevalence of irritable bowel syndrome (IBS) may be due to the application of different diagnostic criteria. New criteria for IBS have been proposed (Rome II). It is unknown whether persons meeting different criteria for IBS have similar psychological and symptom features. The aim of this study was to measure the prevalence of IBS according to Manning and Rome definitions of IBS and to evaluate the clinical and psychological differences between diagnostic categories. METHODS: A total of 4500 randomly selected subjects, with equal numbers of male and female subjects aged > or = 18 yr and representative of the Australian population, took part in this study. Subjects were mailed a questionnaire (response rate, 72%). Characteristics measured were gastrointestinal symptoms over the past 12 months, neuroticism and extroversion (Eysenck Personality Questionnaire), anxiety and depression (Delusions-Symptoms-States Inventory), mental and physical functioning (SF-12), and somatic distress (Sphere). RESULTS: The prevalence for IBS according to Manning, Rome I, and Rome II was 13.6% (95% confidence interval [CI] = 3.5-5.1%), 4.4% (CI 6.0-7.8%), and 6.9% (CI 12.3-14.8%), respectively [corrected]. Only 12 persons with Rome I did not also meet Rome II criteria; 196 persons with Manning criteria did not meet Rome II cut-offs. Having IBS regardless of which criteria were used was significantly associated with psychological morbidity, but psychological factors were not important in discriminating between diagnostic categories. However, pain and bowel habit severity independently discriminated between diagnostic groups. CONCLUSIONS: IBS is a relatively common disorder in the community. The new Rome II criteria may be unnecessarily restrictive in practice.     

Irritable bowel syndrome in a rural community in Bangladesh: prevalence, symptoms pattern, and health care seeking behavior

OBJECTIVE: The aim of this study was to investigate the prevalence of irritable bowel syndrome (IBS) and the pattern of symptoms and health care seeking behavior of IBS subjects in the rural population in Bangladesh. METHODS: This was an observational study to do a positive diagnosis of IBS. A total of 2426 persons > or =15 yr old were interviewed by a predesigned questionnaire based on the Rome criteria. Two villages of a northern district in Bangladesh were included. RESULTS: A response of 95.4% yielded 2426 questionnaires for analysis. Mean age of the surveyed sample was 32.3+/-14.2 yr. In total, 1113 (45.9%) were men, and 1313 (54.1%) were women. Farmers and housewives comprised 2058 (84.8%) persons. The apparent prevalence of IBS was 24.4% with a prevalence of 20.6% in men and 27.7% in women. With strict Rome criteria, the overall prevalence was 8.5% (10.7% in women and 5.8% in men). Age was not found to influence the prevalence in either sex. Other than abdominal pain, the most common IBS symptom was altered stool passage (81.1%). Others in order of frequency were passage of mucus with stool (56.8%), abdominal distension (46.2%), altered stool form (46%), and altered stool frequency (18.2%). Spastic colon pain was noted in 339 (57.2%). IBS subjects with more prevalence of colonic symptoms in the nonspastic group. Drinking milk was found to have a little impact on IBS. A total of 35% IBS subjects consulted doctors for symptoms. Age, sex, and number of symptoms did not influence health care seeking behavior. CONCLUSIONS: IBS is also a problem in rural people in Bangladesh with a prevalence almost identical to most other countries, and only a minority of them seeks health care. Positive diagnosis of IBS can be done by precisely enquiring colonic symptoms in apparently healthy people.     

罗马Ⅲ和罗马Ⅱ标准诊断肠易激综合征的比较

目的比较罗马Ⅲ和罗马Ⅱ标准诊断肠易激综合征（IBS）的符合情况和患者的临床特点。方法面访式问卷调查消化内科门诊连续就诊病例3014例。结果（1）符合罗马Ⅲ标准的IBS患者480例,检出率15．9％（480／3014）。其中便秘型IBS（C—IBS）27．9％（134／480）,腹泻型IBS（D-IBS）32．7％（157／480）,混合型IBS（M-IBS）6．7％（32／480）,未分型IBS（U-IBS）32．7％（157／480）,检出率在各年龄组和性别间差异无统计学意义（P〉0．05）。符合罗马Ⅱ标准的IBS患者558例,检出率为18．5％（558／3014）,其中便秘主导型33．2％（185／558）,腹泻主导型38．2％（213／558）,其他占28．7％（160／558）,女性检出率显著高于男性（P=0．002）,各年龄组间检出率差异无统计学意义。罗马Ⅲ标准对IBS的检出率低于罗马Ⅱ标准（P=0．008）,但两者诊断IBS有较好的一致性。（2）与罗马Ⅱ标准的IBS患者相比,罗马Ⅲ标准的IBS患者腹部症状（P=0．04）和异常排便习惯（P〈0．001）均较严重,最近3个月患者的就诊率也较高（26．5％、35．6％,P=0．02）。（3）罗马Ⅲ标准各亚型的IBS患者的异常排便习惯严重程度差异有统计学意义（C-IBS、M-IBS〉D-IBS〉U-IBS,P〈0．005）,但腹部症状严重程度和患者最近3个月的就诊率之间差异无统计学意义（P〉0．05）。结论罗马Ⅲ和罗马Ⅱ标准诊断IBS具有较好的一致性。与罗马Ⅱ标准相比,罗马Ⅲ标准对IBS的检出率较低,症状频率定义和分型方法相对简单,在临床中更实用,符合其诊断标准的患者症状相对较重,就诊率较高,也较适合于临床试验。     

Comorbidity and use of health-care services among irritable bowel syndrome sufferers

Objective. Patients suffering from irritable bowel syndrome (IBS) have more somatic and psychiatric comorbidity and use more health-care services for comorbid conditions than do other patients. Little is known about the frequency of comorbid symptoms among IBS sufferers in the general population and their influence on use of health-care facilities. The objective of this study was to compare the frequency of somatic and psychiatric symptoms between IBS sufferers and controls in the general population, and to study how comorbidity rates are distributed among consulters and non-consulters and how they predict the use of health care-services. Material and methods. By means of a questionnaire sent to 5000 randomly selected adults IBS was identified according to the Rome II criteria. The questionnaire also covered upper GI symptoms, non-GI somatic symptoms, depression and anxiety. A logistic regression analysis with 26 variables was carried out to determine the independent predictors of health-care seeking for GI and non-GI complaints. Results. The response rate was 73% and prevalence of IBS 5.1% (95% CI 4.4–5.8%). Dyspeptic symptoms, somatic extra-GI symptoms and psychiatric symptoms were reported by 45%, 69% and 51% of IBS sufferers, respectively, and 6%, 35% and 27%, of controls, respectively. Visiting a physician because of GI complaints was associated with disturbing abdominal symptoms, but not with depression or anxiety. Of the present GI conditions, only dyspeptic symptoms were associated with an increased consultation rate also for non-GI complaints. Conclusions. In the general population, both IBS consulters and non-consulters demonstrate high rates of comorbidity. Seeking health care for abdominal complaints is associated with abdominal symptoms rather than psychiatric comorbidity.     

Post-traumatic stress disorder and other co-morbidities in a sample population of patients with irritable bowel syndrome

BACKGROUND: High rates of psychiatric co-morbidity have been reported in patients with irritable bowel syndrome (IBS) and high rates of post-traumatic stress disorder (PTSD) have been reported in fibromyalgia, a disorder also associated with IBS. The primary aim of this study was to assess the frequency of PTSD in IBS patients. METHODS: Sixty-four patients who fulfilled the Rome II diagnostic criteria for IBS were asked to complete questionnaires measuring the prevalence and severity of symptoms of PTSD and psychological distress. RESULTS: Although 86% of IBS patients reported a traumatic life experience, only 7.8% met the diagnostic criteria for PTSD. High rates of somatization, obsessive-compulsive behavior, interpersonal sensitivity, and anxiety symptoms were seen among the IBS patients. CONCLUSIONS: The results show a lower than expected prevalence of PTSD among IBS patients, which is similar to that of the general population. Thus, we did not find that PTSD is over-represented in a sample population of IBS patients.     

Value of different diagnostic criteria for the irritable bowel syndrome among men and women

INTRODUCTION: Whether the diagnostic value of various criteria used to diagnose irritable bowel syndrome (IBS) differ by sex is controversial. AIM: To evaluate the sex-specific value of varying IBS criteria and sex-specific symptoms in patients with IBS and organic disease. METHODS: Outpatients of a gastroenterology practice (64% female) completed a validated questionnaire and received a complete diagnostic work-up as required. Questionnaire data were collected prospectively and audited retrospectively. RESULTS: Overall 233 (male 21%) had a final diagnosis of IBS; 305 (male 47%) received a diagnosis of organic disease. Constipation and bloating were more frequent in females independent whether they had IBS or organic disease. The sensitivity of the diagnostic criteria in male patients was between 82% and 88%, when Manning (3 or more), Rome I or Rome II criteria were applied, whereas the specificity was 65% to 71%. In females, sensitivity was 62% to 64% and specificity was between 66% and 70%. Although all the diagnostic IBS criteria had higher positive predictive values in females versus males, the negative predictive values were lower in females. CONCLUSIONS: Current criteria for IBS differ modestly between sexes, probably reflecting variable prevalence of the disease rather than a sex-specific presentation of IBS.     

Epidemiology of irritable bowel syndrome in Chinese

Irritable bowel syndrome (IBS) is common in Caucasians and Japanese, but its epidemiology has not been studied in urbanized Chinese populations. Our aim was to compare diagnostic criteria and study the epidemiology of IBS in Hong Kong Chinese. In all, 964 subjects from public housing and 334 subjects from private housing were recruited for face-to-face interviews in Shatin, Hong Kong. A structured questionnaire was used to measure the prevalence of IBS according to the Manning, Rome I, and Rome II criteria. The SF-36 scale was used to measure quality of life (QOL) in subjects with IBS and in normal controls. The results were compared by the analysis of covariance (ANCOVA). Relevant medical consultations and absence from work were recorded. There was fair agreement between the Manning and Rome II criteria ( = 0.23; P < 0.001), but good agreement between the Rome I and Rome II criteria ( = 0.5; P < 0.001). The prevalence of IBS, based on the Rome II criteria, was 3.6% (95% CI = 2.0–5.2) in men and 3.8% (95% CI = 2.5–5.2) in women. Men with IBS had significantly lower vitality scores on the SF-36 scale than the controls (P < 0.05 by ANCOVA), and women with IBS had significantly lower mental health scores than controls (P < 0.05 by ANCOVA). In conclusion, IBS is quite prevalent in Hong Kong Chinese, and the QOL of subjects with IBS was significantly affected.     

Prevalence of irritable bowel syndrome in Hong Kong

BACKGROUND AND AIMS: As part of a public education program, the Hong Kong Society of Gastrointestinal Motility studied the prevalence of irritable bowel syndrome (IBS) in the community, which was based on the recently published Rome II criteria. The distribution of diarrhea or constipation-predominant IBS subtypes, the prevalence of bowel symptoms and the predictors of health-care seeking were also studied. METHODS: Among 1797 randomly selected respondents, 1000 successful telephone interviews (56%) were conducted from August 2000 to December 2000, using a validated questionnaire in Chinese that looked into demographic data and various bowel symptoms during the past year. RESULTS: The 12-month prevalence of IBS as defined by the Rome II criteria in Hong Kong was 6.6%. The female to male ratio was 1.3:1, but this ratio was the same in the control group. The distribution of IBS patients into diarrhea predominant, constipation predominant, and non-specific subtypes was 27, 17 and 56%, respectively. The predominant symptom in the IBS group was pain (54.5%), followed by urgency (15%), abdominal distension (15%) and diarrhea (11%). Forty-seven percent of IBS patients sought medical attention and only 21% of them knew that they had IBS. Moderate to severe pain severity (odds ratio 3.7, 95% CI 1.02-13) and mucus in stool (odds ratio 3.57, 95% CI 1.18-10.7) were associated with health-care seeking in univariate analysis. The prevalence of bowel symptoms such as urgency, straining, feeling of incomplete defecation, mucus in stool and abdominal distension ranged from 11 to 41%. CONCLUSION: The prevalence of IBS in Hong Kong was 6.6%, and the female to male ratio was similar to the control group. The majority was of non-specific IBS subtype. Gross underdiagnosis (21%) by Western practitioners was noted.     

Subtypes of irritable bowel syndrome on Rome III criteria: a multicenter study

Background and Aim: The aim of this study was to explore the distribution and clinical characteristics of four subtypes of irritable bowel syndrome (IBS) based on Rome III criteria in Chinese. Methods: A total of 754 consecutive IBS outpatients from three tertiary hospitals in China were included. Diagnostic criteria were based on Rome II or Rome III. Results: Among 754 outpatients, 510 (67.6%) patients met the Rome II criteria, 735 (97.5%) patients met the Rome III criteria and 492 (65.3%) patients met both sets of criteria. Among 735 patients who met the Rome III criteria, 66.3% had IBS with diarrhea (IBS‐D), 14.7% had IBS with constipation (IBS‐C), 4.2% had mixed IBS (IBS‐M) and 14.8% had unsubtyped IBS (IBS‐U). Most of the IBS‐D, IBS‐C and IBS‐M patients based on the Rome III criteria matched the diarrhea‐predominant IBS, constipation‐predominant IBS and alternating IBS based on the Rome II criteria, respectively. Among IBS‐U patients, 57.0%, 33.3% and 9.7% had constipation‐predominant IBS, diarrhea‐predominant IBS and alternating IBS, respectively. For IBS‐M, the frequencies of bowel movements were stable in 48.4% patients and variable in 51.6% patients. Defecation urgency and straining were most frequent in IBS‐M and least frequent in IBS‐U patients than other subtypes. About 77.2% of IBS‐U patients had abnormal stool frequency (< 3 times/week or > 3 times/day). Conclusion: The Rome III criteria are more sensitive and practical in diagnosing IBS. IBS‐D is the most frequent subtype, which is followed by IBS‐U, IBS‐C and IBS‐M. IBS‐U is a new subtype, which warrants further studies.     

An epidemiological survey of constipation in Canada: definitions, rates, demographics, and predictors of health care seeking

OBJECTIVES: The prevalence of functional constipation is highly variable among epidemiological surveys and may relate to the definitions applied. We estimated the population prevalence of self-reported, Rome I-defined, and Rome II-defined constipation in Canada and determined the variables that best predicted health care seeking. METHODS: A research firm was employed to conduct a random digit dial national survey, inviting household members at least 18 yr of age to participate in a study assessing personal health issues. The sample was stratified to ensure that each region of Canada was represented. Data collection involved three stages: 1) recruitment of participants by phone, 2) mailing of the questionnaire, and 3) data retrieval through a follow-up phone call. The Rome II questionnaire was used to derive the prevalence of functional constipation using both Rome I and Rome II criteria. RESULTS: Of the 1149 participants, 27.2% self-reported constipation within the past 3 months, and 16.7% and 14.9% had functional constipation according to Rome I and II, criteria, respectively. For all three definitions, the rate for women was close to twice that for men. Approximately 34% of those with self-reported constipation had visited a physician for it, versus 26.3% of Rome II subjects. In a regression model, subjects self-reporting in the past 3 months were more likely to have seen a doctor for their constipation (odds ratio 2.47, p < 0.01) and significantly more women than men (35.6% vs 19.5%, p < 0.05). CONCLUSIONS: Functional constipation and related health care seeking are common in the Canadian population and are strongly determined by the definition used. The Rome II criteria for this disorder seem to be satisfactory, but modifications may be considered to allow for constipated subjects taking laxatives and to increase the number of qualifying symptoms.     

Detection of bacterial overgrowth in IBS using the lactulose H2 breath test: comparison with 14C-D-xylose and healthy controls

OBJECTIVES Recent reports suggest bacterial overgrowth is commonly associated with irritable bowel syndrome (IBS) when diagnosed using the lactulose hydrogen breath test (LHBT). We employed this test to examine whether similar findings exist in a geographically distinct population of Rome II positive IBS patients and compared it to the 14C-D-xylose breath test, a test with acknowledged greater specificity for bacterial overgrowth. METHODS: In the first series, Rome II IBS patients underwent a 10 g lactulose breath test and a standardized 1 g 14C-D-xylose breath test and answered IBS symptom questionnaires. A positive test required an elevated breath hydrogen concentration within 90 min, two distinct peaks, and an increase >20 ppm. In a second series, control patients lacking gastrointestinal symptoms underwent a lactulose breath test. A positive test required an elevation of breath hydrogen >20 ppm within 90 or 180 min. These criteria were also applied to lactulose breath tests from IBS cases in series one. RESULTS: The IBS patients were predominantly female (64%) and most reported severe symptoms (80%). The majority had diarrhea predominant symptoms (63%) and only 3% were constipation predominant. In the first series, only 10% of patients had a positive lactulose breath test and 13% had a positive 14C-D-xylose test. In the second series, the number of abnormal LHBTs was much higher but no differences were found between IBS patients and controls. CONCLUSION: The lactulose breath test did not reliably detect a common association between bacterial overgrowth and IBS in our patient population.