Transabdominal Electrical Stimulation for Constipation

Inclusion Criteria: * Age over 18 years * Rome III defined constipation (frequency of defecation of less than three times a week, straining or sense of incomplete emptying associated with at least 25% of defecations. Lumpy, hard stools or anal digitation for at least 25% of defecations * Failed Biofeedback * Competent and willing to complete stimulation at home * Competent and willing to complete the questionnaires and bowel diaries Exclusion Criteria: * Rectal prolapse * Active inflammatory bowel disease * Pregnancy or intention to become pregnant during trial * Spinal cord injuries/cauda equina syndrome * Other implanted electrical devices * Allergy to device components * Neurological disorders