Rectal prolapse

What is rectal prolapse?

The rectum is the temporary storage area for bowel motions. Rectal prolapse occurs when the rectum turns itself inside out and comes out through the anus. In the early stages, a portion of the rectum slips out while passing a bowel motion, but it goes back inside by itself. Women are six times more likely to suffer rectal prolapse than men. Children of both sexes under the age of three years are also commonly affected, although the prolapse tends to resolve by itself without the need for surgery. Another type of prolapse is a rectocele, which means the rectum has protruded into the vagina.

What are the types of prolapse?

Rectal prolapse is categorised according to its severity.

• Internal prolapse: the rectum has prolapsed, but not so far as to slip through the anus. This is also known as incomplete prolapse.
  
• Mucosal prolapse: only the interior lining of the rectum protrudes through the anus.
  
• External prolapse: the entire thickness of the rectum protrudes through the anus. This is also known as complete or full thickness prolapse.

• Risk of damage to the rectum, such as ulceration and bleeding
  
• Incarceration, which means the rectum can't be manually pushed back inside the body
  
• Strangulation of the rectum, which means the blood supply is reduced
  
• Death and decay (gangrene) of the strangulated section of rectum.

What are the symptoms?

The symptoms of rectal prolapse depend on the severity, but can include:

• Pain and discomfort in the lower abdomen
  
• Blood and mucus from the anus
  
• The feeling of constipation, or that the rectum is never completely emptied after passing a motion
  
• Protrusion of the rectum through the anus
  
• Leakage of liquefied faeces, particularly following a bowel motion
  
• Faecal incontinence, or reduced ability to control the bowels.

What is the cause?

The exact cause of rectal prolapse is unknown, but risk factors include:

• Chronic constipation
  
• Straining to pass bowel motions
  
• Weakened pelvic floor muscles
  
• Weakened anal sphincter muscles
  
• Weakening of the muscles may be associated with ageing, since rectal prolapse is more common in people aged 65 years and over
  
• Genetic susceptibility, since it appears that some people with rectal prolapse have a blood relative with the same condition
  
• Parasitic infection, such as schistosomiasis
  
• Any condition that chronically increases the amount of pressure within the abdomen, such as benign prostatic hypertrophy, or chronic obstructive pulmonary disease (COPD).

How is it diagnosed?

Rectal prolapse is diagnosed by an examination. In cases of suspected internal prolapse, diagnostic tests may include ultrasound, special x-rays and measurement of the ano-rectal muscle activity (ano-rectal manometry). If the patient has experienced rectal bleeding, the doctor may want to do a number of tests to check for other conditions such as bowel cancer. About 11 per cent of children with rectal prolapse have cystic fibrosis, so it is important to test young patients for this condition too.

What is the treatment?

Treatment depends on the age of the patient and the severity of the prolapse. The treatment options include:

• Diet and lifestyle changes to treat chronic constipation; for example, more fruit, vegetables and wholegrain foods, increased fluid intake and regular exercise. This option is often all that's needed to successfully treat rectal prolapse in young children.
  
• In cases of mucosal prolapse, the structures are secured in place with surgical rubber bands.
  
• Surgery is sometimes used to secure the rectum into place, performed through the abdomen or via the anus. One operation involves tethering the rectum to the central bone of the pelvis (sacrum). Another operation is to remove the prolapsed part of the rectum and to rejoin the bowel to restore near-normal bowel function. While abdominal surgery may give better long-term results, elderly patients may be advised to undergo surgical correction via the anus, since it is easier to recover from this procedure.