Objective Functional constipation (FC) is a common complaint in childhood but the prevalence still remains unclear, the aim of this study was to explore the prevalence of FC in childhood in the northern parts of China. Methods A screening program on FC in childhood was carried out in 5 northern cities (Beijing, Tianjin, Shenyang, Changchun, Harbin) of China according to symptoms under the Rome Ⅲ criteria. Random clustered sampling of the inhabitants was carried out under stratification of cities, geographic zones, schools or nurseries.Sample size of each area was in proportion to the population of the area. The range of age was 4-14. All subjects under study were requested to fill in a questionnaire distributed by the teachers. The screening program was carried out immediately after a section survey was completed. All together, 20 000 questionnaires were distributed with 19 638 retrievals. According to the result of the screening, a small number of patients who met the criteria were further selected to undergo a detailed clinical examination in the hospital including laboratory examination, colonic transit time, defecography or/and barium enema, electromyologram and anorectal manometry to exclude organic disease of the colon. Simultaneously, a detailed questionnaire was requested to fill under the assistance of trained doctors or medical students.Prevalence of FC of the population was adjusted by the rate of correct diagnosis from the detailed study. Results The adjusted point prevalence of FC in 5 northern cities of China according to Rome Ⅲ criteria was 4.73% with higher prevalence rate of FC seen in the Beijing area (5.02%) than in other cities (4.82%, 4.76%, 4.27%, 4.40%, with P＜0.001 ). Male to female ratio was 1.26:1 with majority of the FC fell in the 4-6 year olds (5.76%). Conclusion FC appeared a common disorder in childhood in the northern parts of China which called for greater attention. Higher prevalence was noted in the age groups of 4-6.

OBJECTIVETo explore the symptomatic criteria for diagnosis in children with functional constipation(FC) in North China.

METHODSA screening program for FC in children was carried out in 5 northern cities (Beijing, Tianjin, Shenyang, Changchun, Harbin) of China according to symptoms using Rome III( criteria. Random clustered sampling of the inhabitants was carried out under stratification of city, region and school or kindergarten. Sample size of each area was in proportion to the population of the area. The range of age was 4-14. All the subjects were requested to fill in a questionnaire distributed by the teacher. The screening program was carried out immediately after a plot survey. A total of 20,000 questionnaires were distributed and 19,638 retrieved. According to the result of the screening, a small number of patients who fulfilled the criteria were further selected to undergo detail clinical examinations in the hospital including laboratory examination, colonic transit time, defecography or/and barium enema, electromyogram and anorectal manometry to exclude organic disease of the colon. A detailed questionnaire was filled in with the assistance from a trained doctor or a medical student. Potential risk factors and the relative symptoms were explored by comparing frequencies between FC group and non-FC group using χ2 and Logistic analysis.

RESULTSEighteen symptoms (defecation less than 3 times per week, dry hard sausage-shape stool, difficulty in defecation, abdominal pain, nausea and vomiting, etc) could exist in control group, but FC group had a higher frequency. The difference was statistically significant. Multivariable stepwise logistic regression analysis showed that defecation less than 3 times per week, hard sausage-shape feces, difficulty in defecation, and the need for laxative were associated with FC. The absence of other symptoms had no influence on diagnosis of FC. The sensitivity, specificity and diagnostic accuracy of symptomatic standard diagnostic test based on Rome III( criteria in FC children showed that ≥2 items had the best diagnostic accuracy but moderate sensitivity and specificity.

CONCLUSIONThe symptomatic criteria for FC diagnosis in children are suggested as follows: (1) defecation frequency less than 3 times per week; (2) dry, hard, sausage-shape stool in most defecation; (3) difficulty in most defecation; (4) use of medication or digital evacuation. FC can be considered when 2 of the above 4 criteria are met and the symptoms last at least 2 months.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Constipation ; diagnosis ; etiology ; Female ; Humans ; Reference Standards ; Surveys and Questionnaires