title: Epidemiology of childhood constipation: a systematic review.
abstract: OBJECTIVE
  A systematic review of the published literature was performed to assess the prevalence, incidence, natural history, and comorbid conditions of functional constipation in children.
  
  
  METHODS
  Articles were identified through electronic searches in Medline, Embase, Cochrane Central Library, Cinhal and PsychInfo databases. Study selection criteria included: (1) epidemiology studies of general population, (2) on the prevalence of constipation without obvious organic etiology, (3) in children from 0 to 18 yr old, and (4) published in English and full manuscript form.
  
  
  RESULTS
  Eighteen studies met our inclusion criteria. The prevalence of childhood constipation in the general population ranged from 0.7% to 29.6% (median 8.9; inter quartile range 5.3-17.4). The prevalence of constipation defined as defecation frequency of < 3/wk varied from 0.7% to 29.6% (median 10.4; inter quartile range 1.3-21.3). Identified studies originated from North America (N = 4), South America (N = 2), Europe (N = 9), the Middle-East (N = 1), and Asia (N = 2). Variance of gender specific prevalence was reported in seven studies and five of seven studies reported no significant difference between boys and girls. The age group in which constipation is most common could not be assessed with certainty. Socioeconomic factors were not found to be associated with constipation.
  
  
  CONCLUSIONS
  Childhood constipation is a common problem worldwide. Most studies report similar prevalence rates for boys and girls. Large epidemiologic studies with the use of generally accepted diagnostic criteria are needed to define the precise prevalence of constipation.
authors.affiliation: Department of Pediatric Gastroenterology and Nutrition, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Maartje M
authors.initials: MM
authors.lastname: van den Berg
authors.forename: M A
authors.initials: MA
authors.lastname: Benninga
authors.forename: C
authors.initials: C
authors.lastname: Di Lorenzo
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D003248:Constipation / Q000150:complications / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D017678:Sex Distribution; D012959:Socioeconomic Factors