Surgical treatment of severe constipation
Severe constipation may be treated surgically provided precise evaluation of colon-transit-time and rectal evacuation can be performed. Colon-transit-time may be studied by straight X-ray of the abdomen after oral intake of small plastic markers, and rectal evacuation may be evaluated by defecography. In patients, where Hirschsprung's disease with a short aganglionic segment is suspected, ano-rectal manometry with evaluation of the recto-anal reflex must be performed. Furthermore, electromyography of the external anal sphincter and puborectal muscle during simulated defecation will be necessary in order to evaluate whether obstructed defecation is due to a spastic condition in the anal sphincter or pelvic floor muscles (anismus). Surgical treatment of obstructed defecation depends on the specific pathology, while treatment of slow transit constipation is subtotal colectomy and ileo-rectal anastomosis. In patients, where constipation is based on a combination of obstructed defecation and prolonged colon-transit-time, surgery for obstructed defecation should be carried out first. In patients, where the constipation is due to prolonged colon-transit-time and an adynamic rectum (rectal inertia) without anatomical abnormalities the only possibility of surgical treatment is total colectomy with an ileo-anal pouch.