Effects of Botox in Obstructed Defecation Syndrome

Inclusion Criteria: * Males and females 18 years or older of all races and backgrounds * Competent to give informed consent * Meet the Rome III diagnostic criteria for functional constipation * Inability to relax the puborectalis muscle at electromyography * Altomare Obstructed Defecation Syndrome score of 15 points or above * Failure of treatment with 2 conservative measures which may be as follows: * 1 laxative (osmotic or stimulant) for 2 weeks * 1 fiber supplement for one month * And/or trial of biofeedback for at least 4 sessions Exclusion Criteria: * Previous treatment with Botox (possible antibodies) * Known hypersensitivity to any of the components of the toxin * Medication regimen includes narcotics * Previous radiation therapy to the anal canal and rectum * Prior proctectomy * Presence of unhealed and symptomatic anal fissure * Presence of anal pain * Presence of fecal incontinence * Presence of full thickness rectal prolapse * Presence of internal sphincter myopathy * Inflammatory bowel disease or proctitis * Pregnancy or breast-feeding * Subject is currently enrolled/ just finished participating in a clinical trial in which the intervention/ its carry-over effect may interact with the intervention in this trial