[A study on the symptoms and diagnostic criteria of irritable bowel syndrome in Chinese].

OBJECTIVE

To explore the related symptoms of irritable bowel syndrome (IBS) and its diagnostic criteria in Chinese.

METHODS

Symptomatic IBS was diagnosed using Manning criteria in a screening of 2486 subjects in Beijing. A questionnaire study was carried out randomly by clustering samples of residential groups according to a stratified design of city, suburban and rural areas. The sample size of each area studied was in proportion with the population of the area. Symptoms were recorded in detail by trained doctors and medical students and the results underwent computer analysis by comparing their percentages in an IBS (n = 215) group with those in a non-IBS (n = 2271) group. Single factor analysis was done by using Chi square test, those factors of significance were further analyzed by logistic analysis of multifactor.

RESULTS

In the single factor analysis, as much as 22 symptoms regarding the whole GI tract and urinary bladder were considered to be significantly related to IBS. After multifactor- analysis, those symptoms of colonic origin remain to be most significant; they were: (1) abdominal pain (> 6 times/a), (2) abdominal pain accompanied by altered bowel habits (both diarrhea and constipation), (3) pain released after defecation, (4) mucus in stool.

CONCLUSION

(1) Abdominal pain accompanied by altered bowel habit and pain relieved after defecation are the essential symptoms of IBS. Manning criteria modified by adding constipation with a positive predictive value of 80%, is most suitable in the epidemiologic study as well as in clinical screening of IBS in Chinese; Rome criteria with a positive predictive value of 75% is more reliable in research work and clinical trial. (2) Exclusion of organic disease is important in the diagnosis. (3) There is an overlapping of symptoms between IBS and functional dyspepsia, but those whose colonic symptoms predominate should be diagnosed as IBS, and vise versa. (4) IBS may present extraintestinal symptoms, such as symptoms of the urinary bladder, etc.