Rectal Prolapse

What is a prolapse?

A prolapse is a protrusion of some part of the bowel through and outside the anus. It may occur in childhood or in the elderly. There are three types of prolapse:

1. Incomplete (internal) prolapse: the rectum is not yet protruding through the anus.
2. Mucosal prolapse involving only the inner lining of the rectum.
3. Complete (external) prolapse of the rectum.

What causes prolapse?

The exact cause is not known. Possible explanations are excessive straining at defaecation, a weak pelvic floor and anal sphincter muscles, or a lack of fixation of the lower bowel (rectum) to adjacent pelvic structures. Rectal prolapse is six times more common in women than in men, but is not related to childbirth. It is common in early childhood and usually resolves without surgery in this age group.

Symptoms

Protrusion of the bowel occurs during defaecation which at first goes back by itself. Later it needs to be reduced by hand. There may be discomfort, bleeding and the passage of mucus. Incontinence or poor control of the bowel is a very common complaint. This becomes more severe as the prolapse increases in size. A feeling of constipation or incomplete emptying of the rectum may be an associated symptom.

Diagnosis

Inspection by the doctor is often all that is required after asking the patient to strain. Sometimes it is necessary for the patient to sit on the toilet and strain to produce a prolapse. If a prolapse is suspected but the patient cannot induce it, a special x-ray called a proctogram may be required. If incontinence has been a problem there are tests of sphincter muscle function which can be performed.

Treatment

In children treatment of constipation is usually all that is necessary to correct the prolapse. In adults mucosal prolapse is treated either by rubber banding or by surgery. An incomplete prolapse of the rectum in adults may be treated with bulk laxatives in an attempt to reduce straining with defaecation. If a complete prolapse of the rectum occurs then surgery is usually required. There are several operations available which may be performed either via the abdomen or the anus. Abdominal operations involve securing the bowel to the lower spine (sacrum) and may include removal of a part of the bowel if constipation is a special feature. Laparoscopic (key hole) surgery is currently being evaluated to treat this condition. If the results prove to be as successful as those achieved by major surgery this may become the preferred operation for this condition.

Results

The choice of which procedure is best needs to be decided on an individual basis. Success rates for surgery are very good but vary for each type of operation. Some alteration in bowel habit after operation may occur. This is variable, usually not severe and improves with time.