Rectal Prolapse

Rectal prolapse is the circumferential protrusion of one or more layers of the mucous membrane through the anus. It occurs in two forms. Partial (mucosal) prolapse involves rectal mucosa up to the internal sphincter; complete prolapse involves both the rectal mucosa and the rectal wall.

Rectal prolapse is more common in women than in men and is most common after age 40. It also occurs in children - typically between ages 1 and 3 ­especially those with cystic fibrosis.

Causes

Rectal prolapse is caused by weakening of the ligaments and muscles that hold the rectum in place. In most people with a prolapsed rectum, the anal sphincter muscle is weak. The exact cause of this weakening is unknown; however, rectal prolapse is usually associated with the following conditions:

• Advanced age
• Long-term constipation
• Long-term diarrhea
• Long-term straining during defecation
• Pregnancy and the stresses of childbirth
• Previous surgery
• Cystic fibrosis
• Chronic obstructive pulmonary disease 
• Whooping cough
• Multiple sclerosis
• Paralysis

Signs and Symptoms

The patient may report tissue protrusion from the rectum, which occurs during defecation or some type of exertion such as walking. She may also report one or more of the following problems: a persistent sensation of rectal fullness, mucus discharge, bloody diarrhea, fecal incontinence and, occasionally, lower abdominal pain.

Inspection is used to distinguish between complete and partial prolapse. Complete prolapse involves a protruding rectal mass that exposes the full thickness of the bowel wall and, possibly, a protruding sphincter muscle with mucosa falling into bulky, concentric folds. Partial prolapse involves a partly protruding mucosa and a smaller mass of radial mucosal folds. If necessary, ask the patient to squat before you inspect the prolapse. Sometimes, the prolapse is obvious only when the patient squats.

Diagnostic tests

Physical examination is used to confirm the diagnosis.

Treatment

The type of therapy depends on the symptoms and the underlying cause. Eliminating the cause (straining or coughing) may be the only treatment needed. In a child, prolapsed tissue usually diminishes as the child grows. In an older patient, a sclerosing agent may be injected to cause a fibrotic reaction that fixes the rectum in place. Severe or chronic prolapse requires surgical repair by strengthening or tightening the sphincters with wire or by resecting prolapsed tissue anteriorly or rectally.