Experimental study of faecal continence and colostomy irrigation

Background: Colostomy irrigation is a useful mettled of achieving faecal co ntinence in selected conditions, but remains largely underutilized because it is time consuming. This study investigated the effect of modifying irrig ation technique (route, infusion regimen and pharmacological manipulation) on colonic emptying time in a porcine model. Methods: An end-colostomy and caecostomy were fashioned in six pigs. Twenty markers were introduced into the caecum immediately before colonic irrigat ion. Irrigation route (antegrade or retrograde), infusion regimen (tap wate r, polyethylene glycol (PEG), 1.5 per cent glycine) and pharmacological age nt (glyceryl trinitrate (GTN) 0.25 mg/kg, diltiazem 3.9 mg/kg, bisacodyl 0. 25 mg/ kg) were assigned to each animal at random. Colonic transit was asse ssed by quantifying cumulative expelled markers (CEM) and stool every hour for 12 h. Results: Mean CEM at 6 h for bisacodyl, GTN and diltiazem were 18.17, 12.17 and zero respectively; all pairwise differences in means were significant (P < 0.001). The difference at 12 h between the two routes (P = 0.001) and three fluids (tap water 6.75, glycine 14.83, PEG 16.33; P < 0.001) was sign ificant, but not for PEG versus glycine and bisacodyl versus GTN. Cumulativ e output was significantly more with the antegrade than retrograde route us ing PEG, but the difference in mean cumulative output for bisacodyl and GTN at 12 h was not significant. Conclusion: Colonic emptying is more efficient with antegrade than retrogra de irrigation. PEG and glycine enhance emptying similar to bisacodyl and GT N solution. These findings shelf promise for improved faecal continence by colostomy irrigation and may justify construction of a Malone conduit at th e time of colostomy in selected patients who wish to irrigate.