Bruno Vielle1,2, Antoine Hamy2,3, Aurélien Venara4,5,6. 1. Department of Biostastistics and Methodology, University Hospital of Angers, 4 rue Larrey, 49933, Angers Cedex 9, France. 2. LUNAM, University of Angers, Angers, France. 3. Department of Visceral Surgery, University Hospital of Angers, 4 rue Larrey, 49933, Angers Cedex 9, France. 4. LUNAM, University of Angers, Angers, France. auvenara@yahoo.fr. 5. Department of Visceral Surgery, University Hospital of Angers, 4 rue Larrey, 49933, Angers Cedex 9, France. auvenara@yahoo.fr. 6. UMR INSERM U1235, TENS, The Enteric Nervous System in Gut and Brain Disorders, Institut des Maladies de l'Appareil Digestif, 1, rue Gaston Veil, 44035, Nantes, France. auvenara@yahoo.fr.