title: Infantile hypertrophic pyloric stenosis and achalasia: NO-related or non-related conditions?
abstract: BACKGROUND
  The regulated ability of sphincters to relax allows adequate control of digestive transit. Relaxation of the lower esophageal sphincter (LES) is essential for esophageal emptying and, similarly, pyloric relaxation permits gastric emptying. When the relaxatory response of these sphincters is impaired, luminal transit is altered, as occurs in achalasia and hypertrophic pyloric stenosis. Nitric oxide (NO) has been identified as the main inhibitory neurotransmitter in both sphincteric regions. Moreover, the absence of NO synthase in the LES and the pylorus has been implicated in the pathogenesis of infantile hypertrophic pyloric stenosis (IHPS) and achalasia, respectively.
  
  
  METHODS
  We present the case of a 12-year-old boy diagnosed with these two different conditions attributed to NO absence: IHPS and achalasia.
  
  
  CONCLUSIONS
  To our knowledge this is the first time that such an association has been reported. Whether IHPS and achalasia have been associated in this patient by chance or because they share common pathophysiological mechanisms remains speculative, but is a tantalizing dilemma.
authors.affiliation: Digestive System Research Unit, Hospital General Vall d'Hebron, Autonomous University of Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Castro
authors.forename: F
authors.initials: F
authors.lastname: Mearin
authors.forename: J M
authors.initials: JM
authors.lastname: Gil-Vernet
authors.forename: J R
authors.initials: JR
authors.lastname: Malagelada
mesh_terms: D000015:Abnormalities, Multiple; D002648:Child; D004931:Esophageal Achalasia / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D006984:Hypertrophy; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D011707:Pyloric Stenosis / Q000150:complications* / Q000151:congenital* / Q000503:physiopathology
chemical_list: D009569:Nitric Oxide