Colonic electrical stimulation: Potential use for treatment of delayed colonic transit

Aim: Recently there has been an increased interest in using electrical stimulation to regulate gut motility generally and particularly for the treatment of slow-transit constipation. In this preliminary canine study, we aimed to study the effects of colonic electrical stimulation (CES) on colonic motility and transit. Method: Nine dogs, each equipped with a pair of serosal colon electrodes and a proximal colon cannula were randomized to receive: (i) sham-CES, (ii) long pulse CES (20cpm, 300ms, 6mA) or (iii) pulse train CES (40Hz, 6ms, 6mA). Animals underwent assessment of colonic contractions via manometry, and of colonic transit by inserting 24 radiopaque markers via the colonic cannula and radiographically monitoring the markers at 2, 4 and 6h following their insertion. The colonic transit was assessed by the geometric centre. Results: We found that, compared with sham-CES, pulse train CES, but not long pulse CES, significantly increased the overall colonic motility index twofold and accelerated the colonic transit by 104% at 2h, by 60% at 4h and by 31% at 6h (P=0.01, P=0.02 and P=0.03 vs sham-CES at 2, 4 and 6h, respectively). The accelerating effect of pulse train CES was found to be mediated via both cholinergic and nitrergic pathways. Conclusion: CES with pulse trains has prokinetic effects on colonic contractions and transit in healthy dogs, mediated via the cholinergic and nitrergic pathways. Further clinical studies are warranted to explore the therapeutic potential of CES for slow colonic transit constipation.