title: Mechanisms of intestinal gas retention in humans: impaired propulsion versus obstructed evacuation.
abstract: To explore the clinical role of intestinal gas dynamics, we investigated two potential mechanisms of gas retention, defective propulsion and obstructed evacuation. In healthy subjects, a gas mixture was continuously infused into the jejunum (4 ml/min) 1) during a 2-h control period of spontaneous gas evacuation and 2) during a 2-h test period either with impaired gut propulsion caused by intravenous glucagon (n = 6) or with obstructed (self-restrained) anal evacuation (n = 10) while anal gas evacuation, symptom perception (0-6 scale), and abdominal girth were measured. Impaired gut propulsion and obstructed evacuation produced similar gas retention (558 +/- 68 ml and 407 +/- 85 ml, respectively, vs. 96 +/- 58 ml control; P < 0.05 for both) and abdominal distension (8 +/- 3 mm and 6 +/- 3 mm, respectively, vs. 1 +/- 1 mm control; P < 0.05 for both). However, obstructed evacuation increased symptom perception (2.3 +/- 0.6 score change; P < 0.05), whereas gas retention in the glucagon-induced hypotonic gut was virtually unperceived (-0.4 +/- 0.7 score change; not significant). In conclusion, the perception of intestinal gas accumulation depends on the mechanism of retention.
authors.affiliation: Digestive System Research Unit, Hospital General Vall d'Hebron, Autonomous University of Barcelona, 08035 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Serra
authors.forename: F
authors.initials: F
authors.lastname: Azpiroz
authors.forename: J R
authors.initials: JR
authors.lastname: Malagelada
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000502:physiology; D003672:Defecation / Q000502:physiology; D005260:Female; D005740:Gases / Q000493:pharmacokinetics*; D005765:Gastrointestinal Agents / Q000008:administration & dosage; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D005934:Glucagon / Q000008:administration & dosage; D006801:Humans; D007422:Intestines / Q000502:physiology*; D008297:Male
chemical_list: D005740:Gases; D005765:Gastrointestinal Agents; D005934:Glucagon