Prevalence of Irritable Bowel Syndrome: A Comparison Between Rural and Urban Setting in Bangladesh

Background: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder. The prevalence of irritable bowel syndrome (IBS) varies from 4% to 20% in different Asian nations. Objective: This community-based study was aimed to find out the prevalence of IBS in rural and urban setting in Bangladesh using Rome-III criteria. Methods: This cross-sectional study was conducted with 3500 respondents aged 18 years and above in both rural and urban communities of Bangladesh. The respondents were interviewed using a validated questionnaire in a door-to-door survey. A Rome III criterion was used for diagnosis of IBS. IBS was further classified as constipation predominant, diarrhoea predominant, mixed and un subtype. Statistical analysis was performed with Statistical Package for Social Sciences (SPSS), version 17.0.The level of significance was set at p d” 0.05. Results: The study population consisted almost equal percent respondents from urban (50.1%) and rural (49.9%) community. Among the respondents, 55.06% was male and 44.94% female. Overall prevalence of IBS 7.2% (95% CI, 6.39-8.10) and majority of the participants were associated with IBS belongs to age group 31-40 years with mean age 39.9%. The prevalence of IBS-C, IBS-D, IBS-M, IBS-U were 0.48%, 1.3%, 4.6%, and 0.8% respectively. In rural setting, the prevalence of IBS was 6.5%, (95% CI, 5.46-7.78) and in urban was IBS 7.8% (95% CI, 6.71-9.23). In this study, the prevalence of IBS was higher in males i.e. 57.2% in rural and 52.9% in urban compared with 42.8% in rural and 47.1% in urban females. Conclusion: In conclusion, the prevalence of IBS in urban 7.8% and rural 6.5% among Bangladeshi population. The result of the study suggests that IBS is a major health issue among these respective populations.

Irritable bowel syndrome places an enormous burden on resource challenged healthcare systems. Medical costs for IBS patients were 50% higher than the equivalent costs for non-IBS patients. Increased costs were driven more by frequent use of medical services, including care not directly related to lower GI problems, rather than the cost of prescriptions. 17 There are significant differences between urban and rural populations in Bangladesh in terms of access to healthcare facilities, socio-cultural and environmental factors, which theoretically affect epidemiological characteristics. 16 Only 10-56% of adults with symptoms of IBS present for medical evaluation. 13 This may be related to cultural factors, the existence and degree of pain and psychological disorders, and access to medical care. Women with IBS consult their doctors more frequently than men, although extensive reviews of the literature found no such differences in rural areas of India, Sri Lanka or Bangladesh. However, both urban and rural communities in Bangladesh lack data on all aspects of IBS.
The prevalence of irritable bowel syndrome among rural and urban populations in Bangladesh, and finally discover the pattern of IBS symptoms in the general population of Bangladesh were assessed. of IBS in Singapore (8.6%) and Japan (9.8%) are comparable to that in Australia (6.9%) and Europe (9.6%), although not as high as in Canada and the UK (12%). [9][10][11][12][13] The prevalence of IBS was 24.4% in the first community-based survey using Rome-II criteria in rural Bangladesh and 7.7% in first urban community study in Bangladesh. 14-15 IBS prevalence estimates vary depending on geographical locations and the use of diagnostic criteria. By using Rome-II criteria, authors reported variable prevalence of IBS in national (12.1%), urban (8.5%) and suburban (5%) surveys. Significant differences exist between urban and rural populations in Bangladesh with respect to the access to healthcare, socio-cultural, and environmental factors, which may theoretically affect epidemiological features. 15 Only 10-56% of adults with symptoms of IBS present for medical evaluation. 12 This may relate to cultural factors, the presence and degree of pain and psychological disturbances and access to health care. Women with IBS consult physicians more than men, although such differences were not found in India, Srilanka or in rural Bangladesh through extensive literature review. Nevertheless, data on various aspects of IBS are lacking in both the urban and rural communities of Bangladesh. This study aimed to compare the prevalence of irritable bowel syndrome in rural and urban population in Bangladesh and finally to find out the pattern of symptoms of IBS in general population of Bangladesh.

Materials and Methods
This cross-sectional study was conducted in rural and urban communities in Bangladesh from July 2013 to June 2014 with technical support from the Gastroenterology department of the Shaheed Suhrawardy Medical College & Hospital, Dhaka. The rural community in this study was in Ghior, one of the largest Upzillas in the Manikganj district of Bangladesh. Ghior Upazilla is made up of seven unions, one of which is called "Poila" was selected by lottery, and there is an urban community called Dhaka Uddan of Adabor Thana in Mohammadpur, Dhaka.
The study included all apparently healthy people of any gender over the age of 18 in the regions mentioned. Respondents with functional dyspepsia or organic bowel disease were excluded from the study. People who are unwilling to participate in the study were also excluded from the study.
The sample size was calculated by the N= Z 2 pq/d 2 , p =10% for both urban and rural population. Simple random sampling technique was used in this study. The sample of the study was 3500 respondents who fulfilled the inclusion and exclusion criteria.
Data were collected through face-to-face interviews with respondents who meet the selection criteria. This study used a standard questionnaire based on the Rome III IBS module. The English version of the questionnaire was translated into the native Bengali language by relevant professionals.
IBS was diagnosed on the basis of Rome III criteria, according to which, recurrent abdominal pain or discomfort at least 3 days per month in the last 3 months with onset of symptoms at least 6 months back was essential for suspecting IBS. In addition, to diagnose a person as IBS, the pain needed to be associated with at least 2 out of 3 features which included improvement of pain or discomfort with defecation and onset of pain or discomfort associated with a change in frequency or form of stool. IBS were further sub-classified into diarrhea predominant IBS (IBS-D) constipation predominant IBS (IBS-C) mixed IBS (IBS-M) and un-subtype IBS (IBS-U).
Data were collected by well-trained personnel and medical officers, and supervised by the study investigators prior to the data collection. After selfintroducing themselves and informing the purpose of their visit, the field investigators sought written consent from the respondents for participating in the study. First compile all the relevant data in the main graph and then use the window-based computer software designed by Social Science Statistical Software Package (SPSS-17) (SPSS Inc, Chicago, IL, USA) to perform a statistical analysis of the results. The results are presented in the form of tables, graphs and diagram. Data are expressed as frequency, percentage, average, and standard deviation. The importance of individual symptoms and combined symptoms were analyzed by applying a multivariate logistic regression model adjusted for age and sex. The result was presented as odd ratios with 95% confidence intervals. A two-sided p value less than 0.05 was regarded as statically significant, and 95% confidence intervals was computed using a logistic regression model. The consent form was ensured the right to refuse and withdraw of the participants from the study at any time and also kept confidential. Prior to conduct the study ethical clearance was taken from the ethical review committee of

Results
The study population consisted of 3500 respondents, almost equal percent taken from urban (50.1%) and rural (49.9%) community. In this study, 55.0% male and 44.9% female were interviewed. The majority (29.4%) of the study respondents belonged to age group of 21 to 30 years and male to female ratio was 1.225. Nearly 80.9% of the sample population was married of which 81.4% was female and 80.5% was male. In regards to the occupation of the respondents majority was from housewives (30.0%), about 17.0% from Non-Government employees and about 16% from business and the rest 37% constituted other occupation like, industrial workers, students, drivers and day laborers. With respect to the educational background, 8.04% of the respondents were poorly educated and remaining 16.0% were highly educated (Graduate and above).

Prevalence of Irritable Bowel Syndrome in Rural Setting
Out of 1748 individuals screened for IBS using Rome III criteria in rural community 114 cases were found to be positive, thus giving a prevalence of 6.52% (95% CI, 5.46-7.78). Age-wise distribution showed that majority of individuals associated with IBS belongs to age group 31-40 years (n= 39.4%) followed by age group 21-30 years (n=22.8%) (table III).
Observations: Out of 252 IBS positive patients in this study, it was observed that highly educated and economically solvent patients are prone to develop IBS. Drinking water has no impact on IBS. Logistic regression analysis shows that highly educated persons are more prone to develop IBS. (p=.000) (table IV).

Discussion
The global pooled prevalence of IBS has been estimated to be 11.2% 18 , IBS has a significant impact on patients' quality of life due to physical suffering, psychological co-morbidity, social disability and economic non-productivity. 19,20 It is not always easy to conduct prevalence studies in developing countries including Bangladesh. Due to the high cost, we strive to prospectively estimate the prevalence of irritable bowel syndrome in rural and urban environments in Bangladesh. In this study, 3,500 people were screened for irritable bowel syndrome using the Rome   In this prospective both urban and rural communitybased study, IBS-M with alternating features of diarrhea and constipation was the most common form of IBS in Bangladesh with prevalence of 4.6% followed by IBS-D with prevalence of 1.31%. Predominance of IBS-M among IBS patients has also been reported from the United State. 34 In this study, the prevalence of IBS due to constipation was 0.49%, which may be due to higher fiber intake and faster intestinal transit time in the Indian population. 33 In this study, the prevalence of IBS in men was higher than in women. Although in many Western countries, IBS is more common in women than men; however, no consistent differences have been observed in Asia 11,34,35 Although studies from many Asian countries such as Hong Kong, Taiwan and Singapore did not show gender differences in the prevalence of IBS. Vietnam, Malaysia and Japan report female dominance 23,26 , 36-41 . In the two previous hospital based studies from India, IBS was reported to be more common in males. 21,22 On the other hand, in a community study of non-health seekers in India, the prevalence of IBS among women and men was almost the same. 21 Since India is a male-dominated society, in research conducted in hospital settings and communities, male health-seeking behavior may be the best explanation for the difference in the prevalence of IBS. 42,[43][44][45][46] Considering the current prevalence of IBS in our community, IBS remains an underdiagnosed gastrointestinal disorder. This may be due to poor health-seeking behavior in the community or due to the limited ability of primary health care to diagnose the condition. There are no available studies linking the severity of the illness to the health care seeking pattern of these patients. Therefore, more research is needed to study the health care seeking pattern of IBS patients in our population and assess the severity of IBS. In addition, there are no population studies on the impact of IBS on the health-related quality of life (HRQOL) in Bangladesh. The HRQL assessment of these patients can not only understand the severity of the disease, but also help optimize the treatment of IBS. The advantage of this study is that it is a large sample study based on the community. The prevalence of IBS may vary slightly between rural and urban populations.

Conclusion
The prevalence of IBS in the Bangladeshi population is 7.88% in urban areas and 6.52% in rural areas. It may be concluded that the IBS is a major health problem in Bangladesh and IBS-M is the most frequent subtype followed by IBS-D.