Golden bifid might improve diarrhea-predominant irritable bowel syndrome via microbiota modulation.

OBJECTIVE: Gut microbiota might play a crucial role in the pathogenesis of irritable bowel syndrome (IBS), and probiotics supplement may be an effective treatment option. This study aims to explore the therapeutic effects of Golden bifid on the diarrhea-predominant IBS (IBS-D). METHODS: Twenty-one consecutive IBS-D patients were recruited based on Rome IV criteria. All patients took 2000 mg Golden bifid triple daily for 4 weeks. Gastrointestinal (GI) symptoms, psychological symptoms, small intestine bacterial overgrowth (SIBO) and fecal microbiota characteristics were evaluated in IBS-D patients before and after treatment. RESULTS: After 4-week treatment of Golden bifid, the GI symptoms such as abdominal pain (2.90 ± 1.04 vs. 1.90 ± 1.26, P = 0.002), abdominal distension (2.00 ± 1.34 vs. 1.29 ± 1.31, P = 0.007), diarrhea (3.24 ± 1.37 vs. 1.81 ± 1.21, P = 0.001), defecatory urgency (3.48 ± 1.03 vs. 2.33 ± 1.35, P = 0.000) and incomplete evacuation (2.71 ± 1.15 vs. 1.76 ± 1.26, P = 0.003) were significantly alleviated in IBS-D patients. The Self-Rating Depression Scale (SDS) decreased significantly (46.19 ± 11.36 vs. 43.33 ± 9.65, P = 0.041), and SIBO could be eradicated in 25% (4/16) of IBS-D patients with SIBO. Meanwhile, the abundance of Unclassified Lachnospiraceae and Dorea in genus level and Unclassified Lachnospiraceae, Bacterium Dorea, Bacterium Butyricicoccus and Dorea formicigenerans ATCC 27755 in species level were increased in fecal microbiota (P < 0.05). CONCLUSIONS: Golden bifid could improve most of GI symptoms and depressive symptoms in IBS-D patients and eradicate a small proportion of SIBO in those IBS-D patients with SIBO. What's more, Golden bifid could also modulate the fecal microbiota in IBS-D patients, which implied that the Golden bifid might improve IBS-D via microbiota modulation.

Natural history of adult-onset Ménétrier's disease: Report of a case with 9-year follow-up.

Ménétrier's disease (MD) is a rare disease characterized by markedly hypertrophied gastric mucosal folds typically associated with hypoalbuminemia and anemia. However, the natural history of MD in adults remains unclear and is rarely reported in the literature. The current study presents a case of MD with a 9-year follow-up. A 56-year-old man was diagnosed with MD in 2005. The patient was followed up and underwent surveillance endoscopy once or twice each year. In the present case, the anemia and hypoproteinemia were eliminated following red blood cell transfusion and intravenous iron therapies. The symptoms were relieved after 4 years. Treatment with octreotide had little effect on the gastric mucosa, while antimicrobial combination therapy provided no benefit in the present H. pylori-negative case of MD. In addition, despite abnormalities of the gastric mucosa in the patient persisting after 9 years of follow-up with no evidence of malignancy, malignant transformation in MD should not be overlooked, and regular monitoring of the gastric mucosa via endoscopy is necessary.

The spectra, symptom profiles and overlap of Rome III functional gastrointestinal disorders in a tertiary center in South China.

OBJECTIVE: Most previous studies exploring the overlap of functional gastrointestinal disorders (FGID) focus on the overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). In this study, we aimed to explore the spectra, symptom profiles and overlap of all FGID using the validated Chinese version of the Rome III questionnaire. METHODS: Consecutive newly diagnosed FGID patients who were admitted to the Outpatient Gastroenterology Clinic from 10 May to 10 September 2012 were recruited in the study. All the patients complained of gastrointestinal (GI) symptoms for at least 3 months with a symptom onset of at least 6 months before diagnosis after excluded organic diseases. Patients who met the inclusion criteria were asked to complete the scoring algorithm for the Rome III integrated questionnaire. RESULTS: Among 350 eligible patients, 302 (86.3%) returned completed questionnaires. A total of six major domains including 17 disorders were diagnosed. The four most prevalent FGID were FD (54.6%), IBS (40.7%), unspecified functional bowel disorder (13.9%) and functional constipation (12.6%). The three most prevalent symptoms in FGID were abdominal pain (66.2%), loose stool (58.3%) and abdominal bloating/distension (56.3%). Of the 302 patients, 152 (50.3%) had one to five overlapping FGID. Only functional bloating had no overlap. Six patients had five overlapping FGID simultaneously. In all, 63 patients had overlapping FD and IBS. CONCLUSIONS: This study provided the detailed spectra and symptom profiles for all FGID. Overlapping FGID are common in China.

Improved biopsy accuracy in Barrett's esophagus with a transparent cap.

AIM: To evaluate the efficacy of endoscopy with a transparent cap on biopsy positioning in Barrett's esophagus (BE). METHODS: One hundred and sixty-eight patients with suspected BE at endoscopy were enrolled in our study from November 2007 to December 2009 and divided into two groups: transparent cap group (n = 60) and control group (n = 108). Endoscopy with or without a transparent cap and subsequent biopsy of suspected lesions were performed by five experienced endoscopists in our hospital. In both groups, two biopsy specimens were taken from each patient, and the columnar epithelium or goblet cells in histological assessment were used as the diagnostic standard for BE. RESULTS: In the transparent cap group, 41 cases were tongue type, while 17 and two cases were identified as island type and circumferential type, respectively. In the control group, 65 tongue-type cases were confirmed, with 38 island-type and five circumferential-type cases. Moreover, there was no significant difference with regard to the composition of endoscopic BE types in the two groups (P > 0.05). In the biopsy specimens, BE was detected in 50 cases in the transparent cap group (83.3%, 50/60), whereas the detection rate in the control group (69.4%, 75/108) was lower compared to that in the transparent cap group (P < 0.05). In addition, goblet cells were recognized in only eight cases (all with columnar epithelium) (8/60, 13.3%) in the transparent cap group, with 11 cases in the control group. CONCLUSION: Transparent cap-fitted endoscopy can guide biopsy positioning in BE without other accompanying complications, thus increasing the detection rate of BE.

Prevalence, clinical manifestations and endoscopic features of eosinophilic esophagitis: a pathological review in China.

OBJECTIVE: We aimed to determine the prevalence of eosinophilic esophagitis (EoE) and define its clinical and endoscopic characteristics in Chinese patients. METHODS: Esophageal specimens obtained from January 2006 to December 2010 in the First Affiliated Hospital of Sun Yat-sen University were reviewed, and the data on clinical characteristics and endoscopic findings of patients were obtained. Patients with eosinophils ≥15 per high power field (HPF) were identified as having EoE. RESULTS: A total of 12 patients met the criteria for EoE, establishing a prevalence of 0.34%. These patients presented with dysphagia (4/12, 33.3%), gastroesophageal reflux disease (GERD)-like symptoms (3/12, 25.0%), abdominal pain (3/12, 25.0%) and others (2/12, 16.7%). The most common endoscopic finding was plaques (5/12, 41.7%), and other findings were irregular Z-line (2/12, 16.7%), erosive esophagitis (2/12, 16.7%), white exudates (1/12, 8.3%), linear furrows (1/12, 8.3%), Schatzki ring (1/12, 8.3%), ulcers (1/12, 8.3%) and erythema (1/12, 8.3%). CONCLUSIONS: The prevalence of EoE was 0.34% in our patients. Clinicians should pay attention to patients manifested with dysphagia and GERD-like symptomes with endosopic findings of white exudates, plaques, Schatzki ring and linear furrows.

[A population-based epidemiologic study of bowel habits in Guangdong province].

OBJECTIVE: To determine the bowel habits and its perceptions in the general population of Guangdong province. METHODS: Random clustered sampling involving permanent inhabitants aged 18 - 80 year was carried out under stratification of urban and suburban areas in Guangdong province. Questionnaire included the items on the characteristics of people being selected and their bowel habits. RESULTS: A total of 4103 residents (male 1878, female 2225) were investigated. Mean age among the responders was 42.81 ± 14.13 year. Among 4056 subjects (missing = 47), 2972 subjects (73.3%) reported daily defecation, and 3951 subjects (97.4%) reported stool frequency between 3 times per week and three times per day. Two hundred and seventy subjects (6.6%) reported abnormal bowel habits by themselves. The stool frequency (OR = 2.03, 95%CI: 1.54 - 2.67), forms of stool (OR = 2.75, 95%CI: 2.35 - 3.22) and straining (OR = 3.56, 95%CI: 2.49 - 5.11) were significantly associated with self-reported abnormal bowel habits. Among 3949 subjects (missing = 154), 644 (16.3%) were defined as having abnormal bowel habits according to Rome II criteria. There was poor agreement between self-reported abnormal bowel habits and that defined by Rome II criteria (Kappa = 0.312). CONCLUSION: It seemed to be appropriate that the normal stool frequency was defined as bowel movements between 3 times per week and three times per day in the general population. The prevalence of self-reported abnormal bowel habits was lower than that defined by Rome II criteria and the agreement between these two definitions was poor.

Relationship between symptom response and esophageal pH level on standard dose of esomeprazole treatment for gastroesophageal reflux disease.

BACKGROUND: The relationship between symptom elimination and normalization of esophageal acid level of gastroesophageal reflux disease (GERD) on proton-pump inhibitor (PPI) therapy has been questioned. This study aimed to evaluate the relationship between symptom response and gastro-esophageal acidity control in Chinese patients with GERD on esomeprazole therapy, and to assess the role of 24-hour esophageal pH-metry after therapy in GERD patients. METHODS: GERD patients with typical reflux symptoms were enrolled and received esomeprazole 40 mg once daily for 4 weeks. Patients with positive baseline 24-hour esophageal pH-metry were divided into two groups depending on an additional dual-channel 24-hour pH-metry after treatment. The pH- group achieved normalization of esophageal pH level whereas the pH+ group did not. RESULTS: Of the 80 patients studied, 76 had abnormal baseline esophageal pH levels. Of these, 90% (52/58) of symptom-free patients and 67% (12/18) of symptom-persistent patients achieved esophageal pH normalization after therapy (P = 0.030). The mean post-therapy gastric nocturnal percent time of pH < 4.0 was significantly higher in pH+ group than that in pH- group (P < 0.001) after therapy. The multivariate regression analysis identified hiatus hernia (P < 0.001) and persistent reflux symptom (P = 0.004) were two independent factors predicting the low post-therapy esophageal pH level. CONCLUSIONS: Symptom elimination is not always accompanied by esophageal pH normalization, and vice verse. Esophageal pH-metry is recommended for GERD patients with hiatus hernia or with persistent reflux symptoms after PPI therapy.

Prevalence and risk factors of Barrett's esophagus in patients undergoing endoscopy for upper gastrointestinal symptoms.

OBJECTIVE: To investigate the prevalence of Barrett's esophagus (BE) and its risk factors in patients undergoing endoscopy for upper gastrointestinal symptoms in a Chinese tertiary referral medical center. METHODS: All consecutive patients receiving an endoscopy for upper gastrointestinal symptoms in our medical center from September to December 2007 were recruited. BE was explored for at endoscopy when a suspected columnar-lined esophagus was found. Patients with specialized intestinal metaplasia in the distal esophagus were defined as having BE. RESULTS: A total of 2022 patients (1053 male and 969 female) were recruited. The patients were aged 18 to 88 years and with a mean age of 46.97 +/- 14.84 years. BE was found in 21 patients (15 male and 6 female), a prevalence of 1.0% of all patients receiving endoscopy for upper gastrointestinal symptoms in our medical center. One of the 21 patients had low-grade dysplasia. By logistic multivariate analysis, age (OR 1.03; 95% CI, 1.00, 1.07) and reflux esophagitis (OR 4.44; 95% CI, 1.22, 16.17) were factors associated significantly with BE. CONCLUSION: The prevalence of BE in our study was lower than that reported in other studies, especially in studies from developed countries. Older age and reflux esophagitis may be the risk factors for developing BE.

Prompt upper endoscopy is an appropriate initial management in uninvestigated chinese patients with typical reflux symptoms.

OBJECTIVES: We sought to investigate the prevalence of clinically significant endoscopic findings (CSEFs) in Chinese patients presenting with uninvestigated typical reflux symptoms in the absence of alarm symptoms, and to evaluate whether prompt endoscopy is an appropriate initial management in these patients. METHODS: Consecutive patients presenting with uninvestigated typical reflux symptoms (i.e., heartburn or acid regurgitation) as chief complaints were recruited for symptom evaluation and upper endoscopy, followed by a 2-week proton pump inhibitor (PPI) therapy. RESULTS: Of 469 patients recruited, CSEFs were observed in 180 (38.4%): 154 (32.8%) with erosive esophagitis (EE), 18 (3.8%) with Barrett's esophagus (BE), 24 (5.1%) with peptic ulcer disease (PUD), and 4 (0.9%) with carcinomas (1 esophageal carcinoma and 3 gastric adenocarcinomas). Multivariate analysis identified that an age >50 years (odds ratio (OR)=1.94, P=0.008), male gender (OR=4.11, P<0.001), being overweight or obese (OR=2.99, P<0.001), and alcohol use (OR=9.96, P<0.001) were independent risk factors for EE; an age >50 years (OR=4.61, P=0.003) and alcohol use (OR=5.50, P=0.003) were independent risk factors for BE; and Helicobacter pylori infection (OR=8.52, P<0.001) and alcohol use (OR=4.08, P=0.004) were independent risk factors for PUD. Symptom evaluation and response to PPI treatment were not correlated with EE, BE, and PUD in these patients. CONCLUSIONS: CSEFs other than gastroesophageal reflux disease are present in a considerable proportion of Chinese patients with uninvestigated typical reflux symptoms but without alarm features. Symptom evaluation is of limited practical value, and thus prompt endoscopy seems to be an appropriate initial management option in these patients.

[Side effects of non-steroidal anti-inflammatory drugs on gastric mucosa and preventive effects of teprenone].

OBJECTIVE: To evaluate the side effects of non-steroidal anti-inflammatory drugs (NSAID) on gastric mucosa, and to study the preventive effects of teprenone in patients. METHODS: 108 patients taking NSAID for more than 3 months with no infection of helicobacter pylori (Hp) were collected. All patients were screened by endoscopy and their upper gastrointestinal symptoms were evaluated. Then, 16 patients with ulcers were excluded and 92 patients were randomly divided into intervention group with teprenone and control group. After follow-up for 3 months, patients were screened again by endoscopy and their upper gastrointestinal symptoms were also evaluated. Specimens of gastric mucosa were studied by PAS dyeing, and Cyclooxygenase (COX) level were evaluated by immunohistochemical technique. RESULTS: Of patients taking NSAIDs, the erosion was found in 48 (44.4%) patients while 16 (14.8%) were found with peptic ulcers. The damages were improved significantly (Z = -4.96, P = 0.000) in the intervention group with teprenone (n = 45) as compared with control group (n = 47) after follow-up for 3 months. Both the cox-1 level [31.1% (14/45) vs 6.7% (3/45), P = 0.003] and mucus thickness [66.7% (30/45) vs 13.3% (6/45), P= 0.000] also increased in the intervention group as compared with control group. No significant difference was found on COX-2 level between these two groups [28.9% (13/45) vs 31.1% (14/45), P = 0.82]. CONCLUSION: Long-term use of NSAID caused severe damages on gastric and duodenal mucosa; teprenone improved NSAID-related gastric side effects and increased the COX-1 level and mucus thickness.

Stratification and symptom characteristics of non-erosive reflux disease based on acid and duodenogastroesophageal reflux.

BACKGROUND AND AIM: The subgroups and symptom characteristics of non-erosive reflux disease (NERD) based on acid and duodenogastroesophageal reflux may be different in Chinese patients to Western patients. This study aimed to explore the stratification and symptom characteristics of patients with NERD. METHODS: Patients with typical heartburn and/or acid regurgitation symptoms were enrolled. Each patient filled out a questionnaire. An upper gastrointestinal endoscopy was performed for each patient followed by simultaneous ambulatory 24-h esophageal pH and Bilitec (bilirubin) monitoring. A symptom index (SI) of > or =50% was considered to be positive. RESULTS: Eighty-two consecutive NERD patients were evaluated. Abnormal (NERD pH+) and normal (NERD pH-) 24-h pH tests were found in 24 (29.3%) and 58 (70.7%) patients, respectively. Among 42 NERD pH- patients who reported heartburn symptoms during monitoring, SI was positive in 19 (45.2%) patients (NE-SI+) and negative in 23 (54.8%) patients (NE-SI-). Pathological duodenogastroesophageal reflux (DGER) was found in 43 (52.4%) patients. No significant differences were noted regarding the prevalence of other upper gastrointestinal symptoms, except for acid regurgitation in NERD pH+ and NERD pH- groups. Additionally, no significant differences were seen in the prevalence of other symptoms, except for chest pain, in groups with pathological and normal DGER. CONCLUSION: The proportion of NERD patients with pathological acid reflux was somewhat lower than that reported in Western countries. The role of DGER in NERD may be important. It is difficult to differentiate whether NERD patients have pathological acid or bile reflux according to symptoms.

[A comparison between Rome III and Rome II criteria in diagnosing irritable bowel syndrome].

OBJECTIVE: To determine the degree of agreement of Rome III and Rome II criteria in diagnosing irritable bowel syndrome (IBS) and to compare the clinical difference between the patients diagnosed with these two criteria. METHODS: 3014 patients in the gastrointestinal outpatient department were enrolled consecutively and interviewed face to face with a standard questionnaire. RESULTS: (1) 480 patients were diagnosed as IBS with Rome III criteria. The overall detection rate was 15.9% (480/3014). The proportion of IBS subtypes was as follows: IBS with constipation 27.9% (134/480), IBS with diarrhea 32.7% (157/480), Mixed IBS 6.7% (32/480), Unsubtyped IBS 32.7% (157/480). No difference was observed between different sex and age groups; with Rome II criteria, 558 patients were diagnosed with a detection rate of 18.5% (558/3014). The proportion of IBS subtypes was as follows: constipation predominant IBS 33.2% (185/558), diarrhea predominant IBS 38.2% (213/558), others 28.7% (160/558). The detection rate was higher in female patients (P = 0.002), but there was no difference between different age groups. The detection rate of Rome III criteria was lower than that of Rome II criteria (P = 0.008). There was a good accordance between these two criteria in the diagnosis of IBS (P < 0.01). (2) Patients classified according to Rome III criteria complained more severe abdominal symptoms (P = 0.04) and abnormal bowel habit (P < 0.001) as well as a higher healthcare seeking rate in the last 3 months (35.6% vs 26.5%, P = 0.02) as compared with those classified according to Rome II criteria. (3) According to Rome III criteria, the severity of bowel habit was different among the four subtypes (C-IBS, M-IBS > D-IBS > U-IBS, P < 0.005) while no difference was observed on the abdominal symptoms and the healthcare seeking rates in the last 3 months. CONCLUSIONS: There is a good accordance between Rome II and Rome III criteria in diagnosing IBS. Compared to Rome II criteria, Rome III criteria has a lower detection rate. It is more practical in the clinical practice with clear definition of symptom frequency and easy way of subtyping IBS. The patients diagnosed with Rome III criteria had more severe symptoms and higher healthcare seeking rate, they are more suitable for clinical trial.

[Epidemiology investigation of colorectal cancer on community group in Guangdong province].

OBJECTIVE: To explore the epidemiology characteristics of colorectal cancer on community group in Guangdong province. METHODS: Huidong was took as the research spot to investigate the sickness and incidence of colorectal cancer among a whole community group in Guangdong province, and two projects were used simultaneously: "screening of colorectal cancer in high risk group" and "screening project using fecal occult blood test". The numeration time for population of 10 towns was set at July 1, 2005. Five towns were sampled out from Huidong with 100,859 persons. Meanwhile, the diseases and death cause registering system was established. RESULTS: The incidence of colorectal cancer in Huidong community group was 15.2/100,000 (male 17.2/100,000, female 13.0/100,000), the age-adjusted incidence was 17.6/100,000 (male 19.5/100,000, female 16.7/100,000). The morbidity was 41.9/100,000 (male 46.5/100,000, female 37.2/100,000), the age-adjusted morbidity was 49.0/100,000 (male 54.1/100,000, female 45.6/100,000). The mortality was 5.0/100,000 (male 5.9/100,000, female 4.0/100,000) and the age-adjusted morbidity was 6.4/100,000 (male 7.2/100,000, female 5.7/100,000). CONCLUSION: The incidence of colorectal cancer in Huidong community group is lower than that of high incidence area in China, but gets close to the normal incidence area of China and general level of the world.

[Changes of intercellular spaces of esophageal epithelium in patients with gastroesophageal reflux disease before and after esomeprazole treatment].

OBJECTIVE: To observe the changes of dilated intercellular space (DIS) of esophageal epithelium in different subtypes of gastroesophageal reflux disease (GERD) before and after esomeprazole treatment. METHODS: Nineteen patients with GERD, 6 with erosive esophagitis (EE), 7 with NERD with abnormal acid exposure (NERD pH+), and 6 with NERD with normal acid exposure (NERD pH-), were treated with esomeprazole 40 mg daily for two months. During endoscopy before and after treatment, six biopsy specimens were taken from the apparently normal mucosa 3 - 5 cm above the dentate line in the esophagus to undergo HE staining and histological examination and transmission electron microscopy (TEM). Fifteen normal subjects were used as controls. RESULTS: Two months after the treatment 5 cases (83.33%) in the EE group, 6 cases (85.57%) in the NERD pH+ group, and 5 cases (83.33%) in the NERD pH- group showed a complete recovery of DIS and complete disappearance of the symptom of heartburn. Two of the left three patients who showed incomplete recovery of DIS still had heartburn. CONCLUSION: A complete recovery of DIS 2 months after treatment of esomeprazole is always accompanied by resolution of heartburn symptom. No significant difference in complete recovery of DIS can be found among different GERD subgroups.

[The risk factors and impact of gastroesophageal reflux disease on quality of life in general population].

OBJECTIVES: To assess the risk factors of gastroesophageal reflux disease (GERD) in the general population and its impact on health-related quality of life (HRQOL). METHODS: A face-to-face interview was carried out in Guangdong Province using a validated Chinese version Reflux Disease Questionnaire (RDQ) to assess the prevalence of GERD. Random clustered sampling of permanent inhabitants aged 18 to 90 years was carried out under stratification of urban and suburban areas. The impact of GERD on HRQOL was evaluated using the Chinese version of SF-36. The statistical analysis was performed with SPSS 10.0 programs. RESULTS: A total of 83 GERD patients were collected and 166 healthy subjects were selected as control. There was no difference in prevalence between male (2.6%) and female (2.4%). There was no significant association between age and prevalence of GERD symptoms. Divorced/widowed/separated subjects (OR 4.61) and subjects with severe working burden (OR 3.43) were significantly more likely to report GERD symptoms. As compared with the general population, subjects with GERD symptoms experienced considerable impairment in quality of life. CONCLUSIONS: Psychosocial factors may play important roles in the production of GERD symptoms. GERD has a negative impact on HRQOL.

[Evaluation of the quality of life of patients with irritable bowel syndrome].

OBJECTIVE: To explore and assess the health-related quality of life (HRQOL) of irritable bowel syndrome (IBS) patients in the population. METHODS: Random clustered sampling involving permanent inhabitants aged 18 - 80 yr was carried out under stratification of urban and suburban areas in Guangdong Province. Altogether 231 IBS patients fulfilling the Rome II criteria and 636 Non-IBS as control were collected. The impact of IBS on HRQOL was evaluated using the Chinese version of SF-36. RESULTS: (1) There were no statistically significant differences between IBS and Non-IBS groups in aspects of sex, age educational level, and distribution according to areas (P > 0.05). (2) IBS patients reported significantly poorer HRQOL than controls (Non-IBS) on all SF-36 subscales (P < 0.05). The patients had poorer HRQOL than the Non-patients, but their differences weren't significant (P > 0.05). (3) The scores on all SF-36 subscales were highly associated with the frequency of abdominal pain in IBS patients (P < 0.05); They were also correlated to degree of effects of IBS symptoms on life reported by IBS patients (P < 0.05); The association between the scores and the symptom of fatigue which is the most extra-intestinal symptom in IBS was significant (P < 0.05); (4) Copying style was highly correlated to the eight SF-36 subscales; IBS still had a significant impact on patients after partialing out the effect of copying style. CONCLUSIONS: IBS symptoms had a negative impact on HRQOL and the SF-36 could be adopted to detect the differences between IBS group and Non-IBS group, which may be used as an outcome measure in future treatment studies. However, the development of IBS-specific measures of quality of life is necessary.

[A population-based epidemiologic study of irritable bowel syndrome in Guangdong province].

OBJECTIVE: To explore the prevalence of irritable bowel syndrome (IBS) and its risk factors in Guangdong province. METHODS: A questionnaire was used to screen IBS by face-to-face interviews according to Manning (modified including symptoms of constipation) and Rome II criteria. Random clustered sampling involving permanent inhabitants aged 18 - 80 years was carried out under stratification of urban and suburban areas. Potential risk factors were explored by comparing the frequencies among IBS group and non-IBS group using chi(2) and logistic analysis of multivariate adjusted for age and gender. RESULTS: A total of 4178 residents (male 1907, female 2271) were investigated. Mean age among the responders was (43 +/- 14) years. The response rate was 98%. The adjusted prevalence of IBS in Guangdong province is 5.67% according to the modified Rome II criteria, and is 11.50% according to Manning criteria. There is no difference between urban and suburban areas. The female was predominant in IBS, and the ratio of male to female was 1:1.25 (Rome II) and 1:1.34 (Manning). The age was poorly correlated with the prevalence. Events including history of analgesic use such as NSAID (OR = 3.83), history of food allergies (OR = 2.68), psychological distress (OR = 2.18), life events (OR = 1.89), history of dysentery (OR = 1.63) and negative coping style (OR = 1.28) are highly associated with IBS (P < 0.05). CONCLUSION: IBS is a common disorder in Guangdong Province which deserves greater care and further investigation.