Background and aim: An increase in recto-sigmoid colon activity through electrical stimulation of the sacral dermatomes has previously been reported. It has not been evaluated whether or not sacral dermatome stimulation has beneficial effects on constipation symptoms and anorectal function in constipated patients. Our aim was to evaluate short-term effects of magnetic stimulation of the sacral dermatomes on constipation symptoms and anorectal function in patients with idiopathic slow transit constipation.
Method: Fourteen patients with idiopathic slow transit constipation were enrolled. Constipation symptoms, stool form and anorectal function were assessed before treatment, and at 3 and 6 weeks of treatment. Six-week treatment consisted of either a 3-week period of sham treatment or a 3-week period of magnetic stimulation of the S2-S3 dermatomes, which was performed in a randomized cross-over design.
Results: During the stimulation period, the frequency score of spontaneous bowel movements decreased in eight of the 14 patients (2.9 [2-3]vs 1.4 [0-2]), whose threshold volumes for urge to defecate and maximum tolerable volumes were significantly greater than those of the non-responders, and significantly decreased at the end of treatment. The degree of straining on defecation also significantly decreased in the responders. Responders had shorter right colonic transit time and longer left colonic transit time compared to the non-responders. Sham treatment did not affect constipation symptoms, stool form and rectal sensation.
Conclusion: Sacral dermatome stimulation may offer potential for therapeutic benefit for a subset of patients with idiopathic slow transit constipation, particularly constipated patients with rectal hyposensation or hindgut dysfunction.