title: Colonic pacing in patients with constipation due to colonic inertia.
abstract: BACKGROUND
  The colon exhibits electrical activity in the form of pacesetter potentials (PPs) and action potentials (APs); no activity is recorded in total colonic inertia (TCI). Electrical activity mediates colonic motility. We have elsewhere demonstrated that 4 pacemakers initiate colonic electric activity. We investigated the hypothesis that the absence of electric activity in TCI is due to non-functioning pacemakers and that their stimulation produces colonic motility and defecation.
  
  
  METHODS
  19 patients with TCI were divided into 2 groups: a study group of 11 patients (age 42.6 +/- 6.8 years; 7 women) and a control group of 8 patients (age 41.4 +/- 6.3 years, 5 women). 7 healthy volunteers (age 40.9 +/- 6.1 years, 5 women) were also studied. Pacing electrodes were endoscopically hooked to colonic mucosa: one stimulating and 2 or 3 recording. Stimulating electrodes were applied to the 4 potential pacemaker sites located at the cecal pole, the cecocolonic junction, the mid-transverse colon, and the colosigmoid junction. Electrical activity was recorded before and during electrical stimulation.
  
  
  RESULTS
  Colonic pacing of healthy volunteers caused a significant increase in the frequency, amplitude and conduction velocity of basal electric waves. Colonic pacing in the study group produced PPs and APs, which varied between colonic segments. No waves were recorded from the control group in which the pacemakers were not activated.
  
  
  CONCLUSIONS
  Colonic pacing produces electrical activity in patients with TCI. This method can be applied for the treatment of constipation in these patients.
authors.affiliation: Department of Surgery and Experimental Reseearch, Faculty of Medicine, Cairo University, Egypt. shafik@ahmed-shafik.org
authors.forename: Ahmed
authors.initials: A
authors.lastname: Shafik
authors.forename: Ali A
authors.initials: AA
authors.lastname: Shafik
authors.forename: Olfat
authors.initials: O
authors.lastname: el-Sibai
authors.forename: Ismail
authors.initials: I
authors.lastname: Ahmed
mesh_terms: D000200:Action Potentials; D000328:Adult; D003106:Colon / Q000503:physiopathology; D003248:Constipation / Q000150:complications / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000379:methods*; D004594:Electrophysiology; D005260:Female; D005769:Gastrointestinal Motility; D006801:Humans; D008297:Male; D008875:Middle Aged