Short-term effects of sacral nerve stimulation for idiopathic slow transit constipation

This study assessed the short-term clinical and physiological effect of continuous sacral nerve stimulation in patients with slow transit constipation. Some patients with idiopathic slow transit constipation are unresponsive to conservative treatments, while colectomy has a variable and poorly predictable outcome. Sacral nerve stimulation is a less invasive and reversible procedure that enables direct neuromodulation of the pelvic floor and hindgut. It has been used successfully in the treatment of urologic disorders and fecal incontinence, and some of these patients with concurrent constipation have also noted improved stool frequency and rectal evacuation. Eight women (median age 47 years, median symptom duration 31 years, median stool frequency once per 6 days) were implanted with a temporary percutaneous stimulating S3 electrode for 3 weeks, attached to an external stimulator (Medtronic, Minneapolis,USA). A bowel symptom diary card, anorectal physiological studies, and a radiopaque marker transit study were completed before and during stimulation. Two patients had cessation or marked diminution of symptoms, including normalization of bowel frequency. Colonic transit did not return to normal in any patient. Rectal sensory threshold to distension was decreased during stimulation. Percutaneous temporary sacral nerve stimulation symptomatically improved a minority of patients with resistant idiopathic slow transit constipation. Sensory function was altered by stimulation. Further studies are required to identify patients who may benefit and to assess a range of stimulation parameters.