Background: The aim of this study was to evaluate large bowel transport following antegrade colonic irrigation with a new scintigraphic technique.
Methods: Ten patients (eight with severe constipation, two with faecal incontinence; median age 47 (range 41-66) years) treated with antegrade colonic irrigation took 111In-labelled polystyrene pellets to label the bowel contents. 99mTc-labelled diethylenetriamine penta-acetate was mixed with the irrigation fluid to map its distribution within the large bowel. Scintigraphy was performed before and after a standardized irrigation procedure. The large bowel was divided into four segments. Assuming ordered evacuation of the large bowel, the contribution of each colonic segment to total evacuation was expressed as a percentage of original segmental count. The segmental contributions were added to reach a total defaecation score (range 0-400).
Results: The median defaecation score was 350, corresponding to complete emptying of the rectosigmoid, descending colon, transverse colon, and half of the caecum and ascending colon. The retained irrigation fluid was located throughout the large bowel. Back-flow to the ileum was observed in four patients.
Conclusion: This study used a new scintigraphic technique to assess large bowel transport following antegrade colonic irrigation. Antegrade colonic irrigation induces highly effective emptying even in patients with severe constipation.