Chronic constipation can be aetiopathogenically classified in to slow transit constipation (STC), rectal evacuation difficulty (RED) or a combination (BOTH). Although the efficacy of percutaneous tibial nerve stimulation (PTNS) in faecal incontinence has been well proven, a current literature search identifies only one study which assessed its effect on constipation. We aimed to evaluate the effectiveness of PTNS in patients with different causes of constipation.METHOD:
34 patients (30 women, median age 50 (20-79) years with constipation who had previously failed maximal laxative and biofeedback therapy participated in the study. All patients underwent a baseline radio-opaque marker transit study and anorectal physiology. All had 12 sessions of PTNS of 30 minutes per session. A fall in the Wexner constipation score to ≤15 or by ≥5 points was taken as the primary outcome. Secondary outcomes included the results of pre- and post- PTNS transit and anorectal physiology studies.RESULTS:
There were patients with 11 STC, 14 with RED and 9 with BOTH. A response was seen in four patients (1/11 STC, 2/14 RED and 1/9 BOTH). Comparing pre- and post- PTNS, there was no significant change in the mean Wexner score (p = 0.10). There was no change in colonic transit time among the whole population (p = 0.56) or among those with STC (p=0.47). There was no improvement in balloon expulsion in the whole group (p=0.73) or in patients with RED (p=0.69).CONCLUSION:
Percutaneous tibial nerve stimulation is of no benefit to patients with constipation, whatever aetiopathogenic mechanism is responsible for the symptoms.