title: Colonic response to food in constipation.
abstract: OBJECTIVE
  Colonic response to food is possibly abnormal in constipation.
  
  
  METHODS
  The colonic response to food was evaluated in 323 patients and 60 healthy subjects by following the movements of radiopaque markers after ingestion of a standard 1,000-cal test meal. Constipated patients were divided into four groups: one with a normal, and three with a delayed colorectal transit time. When the delay was found mainly in the ascending colon, the group was labeled as suffering from "colonic inertia". In "hindgut dysfunction", the delay was predominantly found in the descending colon, whereas the term "outlet obstruction" was reserved for constipated patients whose major site of delay was the rectosigmoid area. Colonic response to food was quantified by evaluating the variation of markers in a given abdominal region and the evolution of the geometric center on the entire plain film of the abdomen.
  
  
  RESULTS
  Emptying of the caecum-ascending colon and filling of the rectosigmoid area characterize the colonic response to food in healthy subjects. Constipated patients also filled the rectosigmoid, but different patterns were found in the colon. In constipated patients with transit in the normal range, there was a frequent (41%) absence of colonic response to food as compared to controls (13%) and constipated patients with delayed transit (p<0.0001). The response to food of patients with colonic inertia was similar to that of healthy subjects in terms of distal progression, but less marked. The hindgut dysfunction group emptied the entire left colon but failed to empty the caecum and ascending colon. In the outlet obstruction group, there was no distal progress of the geometric center after meal.
  
  
  CONCLUSIONS
  Abnormal colonic response to food is frequently found in constipated patients, with different patterns according to the type of constipation.
authors.affiliation: Laboratoire de Physiologie Digestive, Hôpital Broussais, Université Paris V, 96 rue Didot, 75014 Paris, France. michel.bouchoucha@brs.ap-hop-paris.fr
authors.forename: Michel
authors.initials: M
authors.lastname: Bouchoucha
authors.forename: Ghislain
authors.initials: G
authors.lastname: Devroede
authors.forename: Alain
authors.initials: A
authors.lastname: Faye
authors.forename: Philippe
authors.initials: P
authors.lastname: Le Toumelin
authors.forename: Pierre
authors.initials: P
authors.lastname: Arhan
authors.forename: Michel
authors.initials: M
authors.lastname: Arsac
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002432:Cecum / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003106:Colon / Q000503:physiopathology*; D003112:Colonic Pseudo-Obstruction / Q000503:physiopathology; D003248:Constipation / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D005502:Food; D005602:France; D005746:Gastric Emptying; D005772:Gastrointestinal Transit; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012007:Rectum / Q000503:physiopathology