From March to November 2018,a cross-sectional study was carried out at 19 kindergartens and 18 primary schools in 12 cities distributed through the four main regions of Mainland China, with anonymous self-administered questionnaires survey which addressed non-neuropathic pediatric BBD. The epidemiological survey performed in the cities was with high population density located throughout Mainland China like Shenzhen(South), Xiamen(Southeast), Zhengzhou(Middle), Xi'an(West) and Harbin(North),etc. Before the investigation, the study protocol was approved by the Chinese Ethics Committee to protect the privacy of the children surveyed, then we administered a previously published validated BBD questionnaire presented to the pediatric institutions, the number of individuals surveyed per school was more than 200.The cross-sectional paper survey used a self-administered anonymous questionnaire filled by children and their caregivers. To ensure the accuracy of the questionnaire, the investigators were specially trained in advance, with whose guidance the questionnaires were filled out by the caregivers. A total of 10587children with ages ranging from 2-8 years were involved in this study. The main contents of the questionnaire include: ①general information (gender, age, height, weight, date of birth, etc.)②using condition of DD after birth (whether DD is used, length of use, number of pieces per day, and whether there are untoward effect, etc.) ③Time of elimination communication (EC) initiation (including potting training, assistant infant’s toilet training)starting time.④current voiding and defecation status, whether to meet the BBD diagnostic criteria.⑤whether or not there is an organic disease that affects urination and defecation. The inclusion criteria of the study were the ones aged 2-8, with functional DUI and/or enuresis and coexisting constipation and/or faecal incontinence. The standard of BBD was defined as the suggestions of ICCS in 2013, used to describe children with a combination of functional bladder and bowel disturbances. It is diagnosed according to the ICD-10 and DSM-V. Meanwhile, the exclusion criteria were children with neuropathic or anatomical abnormalities in the urinary tract or gastrointestinal canal, who were ongoing treatment with anticholinergics, food allergies, inflammatory bowel disease,or any other disorder affecting bladder or bowel function. Children primarily referred with recurrent UTIs were not included in the study.
Besides,definition of children's BBD: children present with lower urinary tract symptoms and defecation dysfunction together, mainly manifested as urinary frequency, urgency, incontinence (sometimes enuresis, droppings, contaminated feces), dysuria, repeated urinary tract infections, constipation or diarrhea, etc. , clinically no evidence of neurological and anatomical organic diseases[1,2,3].SPSS 21.0 statistical software was used for statistical analysis. The quantitative data of the normal distribution were expressed byx±s, and χ2 tests were used to determine significant differences in prevalence of BBD among all youth at different age groups.The mean between groups was compared by t-test and analysis of variance. Multivariate analysis of the incidence of BBD using logistic regression.