Neutrinos help reconcile Planck measurements with the local universe.

Current measurements of the low and high redshift Universe are in tension if we restrict ourselves to the standard six-parameter model of flat ΛCDM. This tension has two parts. First, the Planck satellite data suggest a higher normalization of matter perturbations than local measurements of galaxy clusters. Second, the expansion rate of the Universe today, H0, derived from local distance-redshift measurements is significantly higher than that inferred using the acoustic scale in galaxy surveys and the Planck data as a standard ruler. The addition of a sterile neutrino species changes the acoustic scale and brings the two into agreement; meanwhile, adding mass to the active neutrinos or to a sterile neutrino can suppress the growth of structure, bringing the cluster data into better concordance as well. For our fiducial data set combination, with statistical errors for clusters, a model with a massive sterile neutrino shows 3.5σ evidence for a nonzero mass and an even stronger rejection of the minimal model. A model with massive active neutrinos and a massless sterile neutrino is similarly preferred. An eV-scale sterile neutrino mass--of interest for short baseline and reactor anomalies--is well within the allowed range. We caution that (i) unknown astrophysical systematic errors in any of the data sets could weaken this conclusion, but they would need to be several times the known errors to eliminate the tensions entirely; (ii) the results we find are at some variance with analyses that do not include cluster measurements; and (iii) some tension remains among the data sets even when new neutrino physics is included.

Analytical validation of a multi-protein, serum-based assay for disease activity assessments in multiple sclerosis.

PURPOSE: To characterize and analytically validate the MSDA Test, a multi-protein, serum-based biomarker assay developed using Olink® PEA methodology. EXPERIMENTAL DESIGN: Two lots of the MSDA Test panel were manufactured and subjected to a comprehensive analytical characterization and validation protocol to detect biomarkers present in the serum of patients with multiple sclerosis (MS). Biomarker concentrations were incorporated into a final algorithm used for calculating four Disease Pathway scores (Immunomodulation, Neuroinflammation, Myelin Biology, and Neuroaxonal Integrity) and an overall Disease Activity score. RESULTS: Analytical characterization demonstrated that the multi-protein panel satisfied the criteria necessary for a fit-for-purpose validation considering the assay's intended clinical use. This panel met acceptability criteria for 18 biomarkers included in the final algorithm out of 21 biomarkers evaluated. VCAN was omitted based on factors outside of analytical validation; COL4A1 and GH were excluded based on imprecision and diurnal variability, respectively. Performance of the four Disease Pathway and overall Disease Activity scores met the established acceptability criteria. CONCLUSIONS AND CLINICAL RELEVANCE: Analytical validation of this multi-protein, serum-based assay is the first step in establishing its potential utility as a quantitative, minimally invasive, and scalable biomarker panel to enhance the standard of care for patients with MS.

Quantum stability of chameleon field theories.

Chameleon scalar fields are dark-energy candidates which suppress fifth forces in high density regions of the Universe by becoming massive. We consider chameleon models as effective field theories and estimate quantum corrections to their potentials. Requiring that quantum corrections be small, so as to allow reliable predictions of fifth forces, leads to an upper bound m<0.0073(ρ/10 g cm(-3))(1/3) eV for gravitational-strength coupling whereas fifth force experiments place a lower bound of m>0.0042 eV. An improvement of less than a factor of two in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well controlled and couple to matter with nearly gravitational strength regardless of the specific form of the chameleon potential.

Sustainability in Numbers by Data Analytics.

For a successful delivery of the United Nations Sustainable Development Goals (UNSDGs) and to track the progress of UNSDGs as well as identify the gaps and the areas requiring more attention, periodic analyses on the "research on sustainability" by various countries and their contribution to the topic are inevitable. This paper tracks the trends in sustainability research including the geographical distribution on sustainability research, their level of multi-disciplinarity and the cross-border collaboration, their distribution of funding with respect to the UNSDGs, and the lifecycle analyses. Cumulative publications and patents on sustainability could be fitted to an exponential function, thereby highlighting the importance of the research on sustainability in the recent past. Besides, this analytics quantifies cross-border collaborations and knowledge integration to solve critical issues as well as traditional and emerging sources to undertake sustainability research. As an important aspect of resource sustainability and circular economy, trends in publication and funding on lifecycle assessment have also been investigated. The analytics present here identify that major sustainability research volume is from the social sciences as well as business and economics sectors, whereas contributions from the engineering disciplines to develop technologies for sustainability practices are relatively lower. Similarly, funding distribution is also not evenly distributed under various SDGs; the larger share of funding has been on energy security and climate change research. Thus, this study identifies many gaps to be filled for the UNSDGs to be successful.

Lansoprazole for the prevention of recurrences of ulcer complications from long-term low-dose aspirin use.

BACKGROUND: The role of gastric acid suppression in preventing the recurrence of ulcer complications after the eradication of Helicobacter pylori infection in patients taking long-term low-dose aspirin is uncertain. METHODS: We enrolled 123 patients who had ulcer complications after using low-dose aspirin continuously for more than one month and who had H. pylori infection. After the ulcers had healed and the H. pylori infection was eradicated, the patients were randomly assigned to treatment with 30 mg of lansoprazole daily or placebo, in addition to 100 mg of aspirin daily, for 12 months. The primary end point was the recurrence of ulcer complications. RESULTS: During a median follow-up of 12 months, 9 of the 61 patients in the placebo group (14.8 percent), as compared with 1 of the 62 patients in the lansoprazole group (1.6 percent), had a recurrence of ulcer complications (adjusted hazard ratio, 9.6; 95 percent confidence interval, 1.2 to 76.1). Of these 10 patients, 4 had evidence of a recurrence of H. pylori infection and 2 had taken nonsteroidal antiinflammatory drugs before the onset of complications. Patients in the lansoprazole group were significantly less likely to have a recurrence of ulcer complications than patients in the placebo group (P=0.008). There was no significant difference in mortality between the two groups. CONCLUSIONS: In patients who had ulcer complications related to the long-term use of low-dose aspirin, treatment with lansoprazole in addition to the eradication of H. pylori infection significantly reduced the rate of recurrence of ulcer complications.

Comparison between empirical prokinetics, Helicobacter test-and-treat and empirical endoscopy in primary-care patients presenting with dyspepsia: a one-year study.

AIM: To investigate the optimal strategy to treat dyspeptic patients in primary care. METHODS: Dyspeptic patients presenting to primary care outpatient clinics were randomly assigned to: (1) empirical endoscopy, (2) H pylori test-and-treat, and (3) empirical prokinetic treatment with cisapride. Early endoscopy was arranged if patients remained symptomatic after 2 wk. Symptom severity, quality-of-life (SF-36) as well as patient preference and satisfaction were assessed. All patients underwent endoscopy by wk 6. Patients were followed up for one year. RESULTS: Two hundred and thirty four patients were recruited (163 female, mean age 49). 46% were H pylori positive. 26% of H pylori tested and 25% of empirical prokinetic patients showed no improvement at wk 2 follow-up and needed early endoscopy. 15% of patients receiving empirical cisapride responded well to treatment but peptic ulcer was the final diagnosis. Symptom resolution and quality-of-life were similar among the groups. Costs for the three strategies were HK dollar 4343, dollar 1771 and dollar 1750 per patient. 66% of the patients preferred to have early endoscopy. CONCLUSION: The three strategies are equally effective. Empirical prokinetic treatment was the least expensive but peptic ulcers may be missed with this treatment. The H pylori test-and-treat was the most cost-effective option.

Differing coping mechanisms, stress level and anorectal physiology in patients with functional constipation.

AIM: To investigate coping mechanisms, constipation symptoms and anorectal physiology in 80 constipated subjects and 18 controls. METHODS: Constipation was diagnosed by Rome II criteria. Coping ability and anxiety/depression were assessed by validated questionnaires. Transit time and balloon distension test were performed. RESULTS: 34.5% patients were classified as slow transit type of constipation. The total colonic transit time (56 h vs 10 h, P<0.0001) and rectal sensation including urge sensation (79 mL vs 63 mL, P = 0.019) and maximum tolerable volume (110 mL vs 95 mL, P = 0.03) differed in patients and controls. Constipated subjects had significantly higher anxiety and depression scores and lower SF-36 scores in all categories. They also demonstrated higher scores of 'monitoring' coping strategy (14+/-6 vs 9+/-3, P = 0.001), which correlated with the rectal distension sensation (P = 0.005), urge sensation (P=0.002), and maximum tolerable volume (P = 0.035). The less use of blunting strategy predicted slow transit constipation in both univariate (P = 0.01) and multivariate analysis (P = 0.03). CONCLUSION: Defective or ineffective use of coping strategies may be an important etiology in functional constipation and subsequently reflected in abnormal anorectal physiology.

Cryoablation for the treatment of occipital neuralgia.

BACKGROUND: Treatment of occipital neuralgia (ON) can be complex, though many treatment options exist. Cryoablation (CA) is an interventional modality that has been used successfully in chronic neuropathic conditions and is one such option. OBJECTIVE: To study and evaluate the efficacy and safety of cryoablation for treatment of ON. STUDY DESIGN: Retrospective evaluation. SETTING: Academic university-based pain management center. METHODS: All patients received local anesthetic injections for ON. Patients with greater than or equal to 50% relief and less than 2 week duration of relief were treated with CA. RESULTS: Thirty-eight patients with an average age of 49.6 years were included. Of the 38 patients, 20 were treated for unilateral greater ON, 10 for unilateral greater and lesser ON, and 8 for bilateral greater ON. There were 10 men and 28 women, with an average age of 45.2 years and 51.1 years, respectively. The average relief for all local anesthetic injections was 71.2%, 58.3% for patients who reported 50 - 74% relief (Group 1) and 82.75% for patients who reported greater than 75% relief (Group 2). The average improvement of pain relief with CA was 57.9% with an average duration of 6.1 months overall. Group 1 reported an average of 45.2% relief for an average of 4.1 months with CA. In comparison, Group 2 reported an average of 70.5% relief for 8.1 months. The percentage of relief (P = 0.007) and duration of relief (P = 0.0006) was significantly improved in those reporting at least 75% relief of pain with local anesthetic injections (Group 2 vs Group 1). Though no significance in improvement from CA was found in men, significance was seen in women with at least 75% benefit with local anesthetic injections in terms of duration (P = 0.03) and percentage (P = 0.001) of pain relief with CA. The average pain score prior to CA was 8 (0 - 10 visual analog scale, VAS), this improved to 4.2, improvement of 3.8 following CA at 6 months (P = 0.03). Of the 38 patients, 3 (7.8%) adverse effects were seen. Two patients reported post procedure neuritis and one was monitored for procedure-related hematoma. LIMITATIONS: Study limitations include the retrospective nature of the study. Additionally, only the percentage of relief, pain score, and duration of relief were collected. CONCLUSIONS: CA is safe, and should be considered in patients with ON. KEY WORDS: Cryoablation, cryoanalgesia, occipital neuralgia, treatment, adverse effects.

Effects of primary metronidazole and clarithromycin resistance to Helicobacter pylori on omeprazole, metronidazole, and clarithromycin triple-therapy regimen in a region with high rates of metronidazole resistance.

The aim of this study was to investigate the effect of metronidazole resistance (MtzR) and clarithromycin resistance (ClaR) on the eradication rate for omeprazole, clarithromycin, and metronidazole triple-therapy regimen and on the development of posttherapy drug resistance in a region of high rates of MtzR. One hundred ninety-six Helicobacter pylori isolates were recovered from patients with duodenal ulcer, gastric ulcer, or nonulcer dyspepsia during upper endoscopy. The prevalences of MtzR, ClaR, and dual resistance were 37.8%, 13.8%, and 8.7%, respectively. The intention-to-treat eradication rates for metronidazole-susceptible (87.2% vs. 67.6%; P=.001) and clarithromycin-susceptible (86.4% vs. 40.7%; P<.001) strains were significantly higher than the rates for resistant strains. Multiple logistic regression analysis implicated younger age (<40 years old), MtzR, ClaR, and the diagnosis of nonulcer dyspepsia as independent factors that predicted treatment failure. The rates of posttreatment MtzR, ClaR, and dual resistance were 88%, 88%, and 75%, respectively. MtxR and ClaR significantly affected the success of eradication therapy. Posttreatment rates of resistance were high and were related to the presence of pretreatment antibiotic resistance.

Psychosocial factors in patients with noncardiac chest pain.

OBJECTIVE: This study sought to explore some psychosocial factors that distinguished individuals with noncardiac chest pain (NCCP) from those without NCCP, and whether these psychosocial factors were associated with anxiety and depression that are co-morbid factors of NCCP. METHODS: A matched case-control design was adopted to compare differences in psychosocial factors among a target group of patients with NCCP (N = 70), a pain control group of patients with rheumatism (N = 70), and a community control group of healthy individuals (N = 70). RESULTS: Compared with subjects from the two control groups, NCCP patients tended to monitor more, use more problem-focused coping, display a coping pattern with a poorer strategy-situation fit, and receive less emotional support in times of stress. Moreover, monitoring perceptual style and problem-focused coping were associated with higher levels of anxiety and depression. Coping pattern with a strategy-situation fit and emotional support were related to lower levels of anxiety and depression. CONCLUSIONS: The present new findings suggest that monitoring perceptual style and inflexible coping style are risk factors that enhance one's vulnerability to NCCP. Emotional support may be a resource factor that reduces one's susceptibility to NCCP.

Population based study of noncardiac chest pain in southern Chinese: prevalence, psychosocial factors and health care utilization.

AIM: Population-based assessment of noncardiac chest pain (NCCP) is lacking. The aim of this study was to evaluate the prevalence, psychosocial factors and health seeking behaviour of NCCP in southern Chinese. METHODS: A total of 2 209 ethnic Hong Kong Chinese households were recruited to participate in a telephone survey to study the epidemiology of NCCP using the Rose angina questionnaire, a validated gastroesophageal reflux disease (GERD) questionnaire and the hospital anxiety-depression scale. NCCP was defined as non-exertional chest pain according to the Rose angina questionnaire and had not been diagnosed as ischaemic heart diseases by a physician. RESULTS: Chest pain over the past year was present in 454 subjects (20.6%, 95% CI 19-22), while NCCP was present in 307 subjects (13.9%, 95% CI 13-15). GERD was present in 51% of subjects with NCCP and 34% had consulted a physician for chest pain. Subjects with NCCP had a significantly higher anxiety (P<0.001) and depression score (P=0.007), and required more days off (P=0.021) than subjects with no chest pain. By multiple logistic regression analysis, female gender (OR 1.9, 95% CI 1.1-3.2), presence of GERD (OR 2.8, 95% CI 1.6-4.8), and social life being affected by NCCP (OR 6.9, 95% CI 3.3-15.9) were independent factors associated with health seeking behaviour in southern Chinese with NCCP. CONCLUSION: NCCP is a common problem in southern Chinese and associated with anxiety and depression. Female gender, GERD and social life affected by chest pain were associated with health care utilization in subjects with NCCP.

Antralization at the edge of proximal gastric ulcers: does Helicobacter pylori infection play a role?

AIM: To determine the prevalence of antralization at the edge of proximal gastric ulcers, and the effect of H. pylori eradication on the mucosal appearances. METHODS: Biopsies were taken from the antrum, body and the ulcer edge of patients with benign proximal gastric ulcers before and one year after treatment. Gastric mucosa was classified as antral, transitional or body type. H. pylori positive patients received either triple therapy, or omeprazole. RESULTS: Patients with index ulcers in the incisura, body or fundus (n=116) were analyzed. Antral-type mucosa was more prevalent at the ulcer edge in H. pylori-positive patients than H. pylori-negative patients (93 % vs 60 %, OR=8.95, 95 %CI: 2.47-32.4, P=0.001). At one year, there was a significant reduction in the prevalence of antralization (from 93 % to 61 %, P=0.004) at the ulcer edge in patients with H. pylori being eradicated. However, there was no difference in the prevalence of antralization at the ulcer edge in those with persistent infection. CONCLUSION: H. pylori infection is associated with antralization at the edge of proximal gastric ulcers, which may be reversible in some patients after eradication of the infection.

Bronchoscopy of cetaceans.

Bronchoscopy is a standard diagnostic and therapeutic procedure in respiratory medicine and has been performed on many animal species. Cetaceans suffer considerable morbidity and mortality from lower respiratory tract infections, and it is very difficult to sample lower respiratory tract secretions for microbiology and other analyses. We report our experience on performing fiberoptic bronchoscopy in three bottle-nosed dolphins (Tursiops truncatus) and one false killer whale (Pseudorca crassidens), which should help other clinicians in performing bronchoscopy in cetaceans.

Helicobacter pylori eradication to prevent gastric cancer in a high-risk region of China: a randomized controlled trial.

CONTEXT: Although chronic Helicobacter pylori infection is associated with gastric cancer, the effect of H pylori treatment on prevention of gastric cancer development in chronic carriers is unknown. OBJECTIVE: To determine whether treatment of H pylori infection reduces the incidence of gastric cancer. DESIGN, SETTING, AND PARTICIPANTS: Prospective, randomized, placebo-controlled, population-based primary prevention study of 1630 healthy carriers of H pylori infection from Fujian Province, China, recruited in July 1994 and followed up until January 2002. A total of 988 participants did not have precancerous lesions (gastric atrophy, intestinal metaplasia, or gastric dysplasia) on study entry. INTERVENTION: Patients were randomly assigned to receive H pylori eradication treatment: a 2-week course of omeprazole, 20 mg, a combination product of amoxicillin and clavulanate potassium, 750 mg, and metronidazole, 400 mg, all twice daily (n = 817); or placebo (n = 813). MAIN OUTCOME MEASURES: The primary outcome measure was incidence of gastric cancer during follow-up, compared between H pylori eradication and placebo groups. The secondary outcome measure was incidence of gastric cancer in patients with or without precancerous lesions, compared between the 2 groups. RESULTS: Among the 18 new cases of gastric cancers that developed, no overall reduction was observed in participants who received H pylori eradication treatment (n = 7) compared with those who did not (n = 11) (P =.33). In a subgroup of patients with no precancerous lesions on presentation, no patient developed gastric cancer during a follow-up of 7.5 years after H pylori eradication treatment compared with those who received placebo (0 vs 6; P =.02). Smoking (hazard ratio [HR], 6.2; 95% confidence interval [CI], 2.3-16.5; P<.001) and older age (HR, 1.10; 95% CI, 1.05-1.15; P<.001) were independent risk factors for the development of gastric cancer in this cohort. CONCLUSIONS: We found that the incidence of gastric cancer development at the population level was similar between participants receiving H pylori eradication treatment and those receiving placebo during a period of 7.5 years in a high-risk region of China. In the subgroup of H pylori carriers without precancerous lesions, eradication of H pylori significantly decreased the development of gastric cancer. Further studies to investigate the role of H pylori eradication in participants with precancerous lesions are warranted.

Colonoscopy demand and practice in a regional hospital over 9 years in Hong Kong: resource implication for cancer screening.

BACKGROUND: The incidence of colorectal cancer (CRC) in Hong Kong is rising. The trend of colonoscopy demand is uncertain. AIM: To investigate colonoscopy demand and practice in a Hong Kong regional hospital over the past nine years. METHODS: Colonoscopy data from 1st January 1997 to 31st August 2005 were retrieved and divided into two equal periods for comparison. Colonoscopy practice and findings between the two periods were compared. RESULTS: There was no change in the number of endoscopists and colonoscopy sessions in the two periods. The number of colonoscopy done in the two periods was 2,681 and 2,871, respectively. The indications for screening of CRC/polyp (9.3 vs. 24.7%, p < 0.0001) and surveillance of CRC/polyp (4.7 vs. 10.9%, p < 0.0001) were increased, but decreased for diarrhea (18 vs. 10.2%, p < 0.0001) and per rectal bleeding (19 vs. 8.1%, p < 0.0001). The waiting time was lengthened from 2 to 4 weeks (p < 0.0001). The percentage of colonic adenomas (19.9 vs. 27.2%, p < 0.0001) was increased. A right-shift was observed in both CRC (37 vs. 50%, p = 0.018) and adenoma (21.6 vs. 38.1%, p < 0.0001). CONCLUSION: The number of colonoscopies performed was governed by capacity partly through lengthening of waiting time to cope with demand. Ways to improve capacity for colonoscopies is needed.

Esomeprazole with aspirin versus clopidogrel for prevention of recurrent gastrointestinal ulcer complications.

BACKGROUND AND AIMS: The role of clopidogrel in patients at risk for gastrointestinal complications is uncertain, although it has been recommended for patients who have gastrointestinal intolerance to aspirin. We tested the hypothesis that clopidogrel is as effective as esomeprazole and aspirin in preventing recurrences of ulcer complications. METHODS: This was a prospective, double-blind, randomized, controlled study of 170 patients who developed ulcer bleeding after the use of low-dose aspirin between November 2002 and January 2005. After healing of ulcers and eradication of Helicobacter pylori, if present, patients were assigned randomly to treatment with esomeprazole 20 mg/day and aspirin 100 mg/day (n = 86) or clopidogrel 75 mg/day (n = 84) for 52 weeks. The primary end point was recurrent ulcer complications. RESULTS: During a median follow-up period of 52 weeks, no patient in the esomeprazole group, as compared with 9 patients in the clopidogrel group, developed recurrent ulcer complications. The cumulative incidences of recurrent ulcer complications were 0% in patients receiving esomeprazole and aspirin and 13.6% in patients receiving clopidogrel (absolute difference, 13.6%; 95% confidence interval for the difference, 6.3-20.9; log-rank test, P = .0019). CONCLUSIONS: The combination of esomeprazole and aspirin is superior to clopidogrel in preventing ulcer complications in patients who have a past history of aspirin-related peptic ulcer bleeding.

Weighing neutrinos with galaxy cluster surveys.

Large future galaxy cluster surveys, combined with cosmic microwave background observations, can achieve a high sensitivity to the masses of cosmologically important neutrinos. We show that a weak lensing selected sample of > or approximately 100,000 clusters could tighten the current upper bound on the sum of masses of neutrino species by an order of magnitude, to a level of 0.03 eV. Since this statistical sensitivity is below the best existing lower limit on the mass of at least one neutrino species, a future detection is likely, provided that systematic errors can be controlled to a similar level.

Celecoxib compared with lansoprazole and naproxen to prevent gastrointestinal ulcer complications.

PURPOSE: Selective cyclooxygenase-2 (COX-2) inhibitors cause significantly fewer peptic ulcers than conventional nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) in patients at low risk or high risk for peptic ulcers. On the other hand, proton pump inhibitor co-therapy has also been shown to be effective in preventing relapse of peptic ulcers in high-risk patients using nonselective NSAIDs. We compared the efficacy of a selective COX-2 inhibitor with that of proton pump inhibitor co-therapy in the reduction in the incidence of ulcer relapse in patients with a history of NSAID-related peptic ulcers. MATERIALS AND METHODS: For this study, we recruited 224 patients who developed ulcer complications after NSAID use. We excluded patients who required concomitant aspirin treatment and who had renal impairment. After healing of ulcers and eradication of Helicobacter pylori, patients were randomly assigned to treatment with celecoxib 200 mg daily (n = 120) or naproxen 750 mg daily and lansoprazole 30 mg daily (n = 122) for 24 weeks. The primary endpoint was recurrent ulcer complications. RESULTS: During a median follow-up of 24 weeks, 4 (3.7%, 95% confidence interval [CI] 0.0%-7.3%) patients in the celecoxib group, compared with 7 patients (6.3%, 95% CI 1.6%-11.1%) in the lansoprazole group, developed recurrent ulcer complications (absolute difference -2.6%; 95% CI for the difference -9.1%-3.7%). Celecoxib was statistically non-inferior to lansoprazole co-therapy in the prevention of recurrent ulcer complications. Concomitant illness (hazard ratio 4.72, 95% CI 1.24-18.18) and age 65 years or more (hazard ratio 18.52, 95% CI 2.26-142.86) were independent risk factors for ulcer recurrences. Significantly more patients receiving celecoxib (15.0%, 95% CI 9.7-22.5) developed dyspepsia than patients receiving lansoprazole (5.7%, 95% CI 2.8-11.4. P = .02). CONCLUSIONS: Celecoxib was as effective as lansoprazole co-therapy in the prevention of recurrences of ulcer complications in subjects with a history of NSAID-related complicated peptic ulcers. However, celecoxib, similar to lansoprazole co-therapy, was still associated with a significant proportion of ulcer complication recurrences. In addition, more patients receiving celecoxib developed dyspepsia than patients receiving lansoprazole and naproxen.

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.