Inclusion Criteria:  Patients who are psychologically stable and suitable for intervention and able to provide informed consent Patients with symptoms of faecal incontinence for solid or liquid stool Patients who have had successful outcome from temporary SNS Patients who are willing and competent to fill in questionnaires and undergo an extra CT and MRI scan during the study  Exclusion Criteria:  Patients who are claustrophobic to undertake MRI scan Patients who had previous devices implanted that may be magnetically, electrically, mechanically activated or affected by MRI scan Pregnant patients Patients who are breastfeeding Patients who are psychologically unstable and unsuitable for intervention and unable to provide informed consent Patients who did not successfully pass the trial of SNS temporary SNS)