title: Abdomino-phrenic dyssynergia in patients with abdominal bloating and distension.
abstract: OBJECTIVE
  The abdomen normally accommodates intra-abdominal volume increments. Patients complaining of abdominal distension exhibit abnormal accommodation of colonic gas loads (defective contraction and excessive protrusion of the anterior wall). However, abdominal imaging demonstrated diaphragmatic descent during spontaneous episodes of bloating in patients with functional gut disorders. We aimed to establish the role of the diaphragm in abdominal distension.
  
  
  METHODS
  In 20 patients complaining of abdominal bloating and 15 healthy subjects, we increased the volume of the abdominal cavity with a colonic gas load, while measuring abdominal girth and electromyographic activity of the anterior abdominal muscles and of the diaphragm.
  
  
  RESULTS
  In healthy subjects, the colonic gas load increased girth, relaxed the diaphragm, and increased anterior wall tone. With the same gas load, patients developed significantly more abdominal distension; this was associated with paradoxical contraction of the diaphragm and relaxation of the internal oblique muscle.
  
  
  CONCLUSIONS
  In this experimental provocation model, abnormal accommodation of the diaphragm is involved in abdominal distension.
authors.affiliation: Digestive System Research Unit, University Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Villoria
authors.forename: Fernando
authors.initials: F
authors.lastname: Azpiroz
authors.forename: Emanuel
authors.initials: E
authors.lastname: Burri
authors.forename: Daniel
authors.initials: D
authors.lastname: Cisternas
authors.forename: Alfredo
authors.initials: A
authors.lastname: Soldevilla
authors.forename: Juan-R
authors.initials: JR
authors.lastname: Malagelada
mesh_terms: D000005:Abdomen / Q000503:physiopathology; D034861:Abdominal Wall / Q000503:physiopathology*; D000328:Adult; D003106:Colon / Q000503:physiopathology*; D005260:Female; D005414:Flatulence / Q000503:physiopathology*; D005740:Gases; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011187:Posture
chemical_list: D005740:Gases