title: Review article: Chronic constipation and food hypersensitivity--an intriguing relationship.
abstract: BACKGROUND
  Chronic constipation is common in the general population. Some studies have shown that in children cow's milk protein hypersensitivity can cause chronic constipation unresponsive to laxative treatment.
  
  
  OBJECTIVE
  To review the literature and summarize the data that point to a relationship between refractory chronic constipation and food hypersensitivity, and to discuss the hypothesis that the pathogenesis of constipation due to food hypersensitivity.
  
  
  METHODS
  A search in the U.S. National Library of Medicine was performed, matching the key words 'chronic constipation, food intolerance and allergy'.
  
  
  RESULTS
  Thirty-three papers were found but only 19 of them were related to the topic of this review. Most of the data indicated a relationship between constipation and food allergy in a subgroup of paediatric patients with 'idiopathic' constipation unresponsive to laxative treatment. There was only one study in adults that demonstrated the resolution of chronic constipation on hypoallergenic diet in four patients.
  
  
  CONCLUSIONS
  An increasing number of reports suggest a relationship between refractory chronic constipation and food allergy in children. Similar data in adults are scarce and need to be confirmed. Further studies should be performed to obtain firmer evidence for the role of allergy in constipation and clarify the pathogenetic mechanisms involved.
authors.affiliation: Internal Medicine, University Hospital of Palermo, Palermo, Italy. acarroccio@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Carroccio
authors.forename: G
authors.initials: G
authors.lastname: Iacono
mesh_terms: D002648:Child; D002908:Chronic Disease; D003248:Constipation / Q000175:diagnosis / Q000209:etiology*; D003937:Diagnosis, Differential; D005512:Food Hypersensitivity / Q000150:complications* / Q000175:diagnosis; D006801:Humans