What is rectal prolapse?

Rectal prolapse is the protrusion of the rectum through the anal canal and outside the anus. It is a socially debilitating condition and patients can experience an array of debilitating symptoms including faecal incontinence, constipation and obstructed defecation that can have a significant impact on their quality of life.

There are two types of rectal prolapse:

  1. Internal prolapse where the rectum is not yet protruding through the anus
  2. External prolapse where the rectum is protruding through the anus

Rectal prolapse is six times more common in women than in men. The exact cause of rectal prolapse is unknown. However, there are several anatomical and physiological factors that contribute to the development of rectal prolapse. These factors include an abnormal laxity of the internal and external anal sphincters and the pelvic floor muscles, weak fixation of the rectum to adjacent pelvic structures, redundant sigmoid, and chronic constipation.

Symptoms of rectal prolapse

External prolapse presents as a lump (bowel) protruding through the anus during defecation and goes back by itself. With time, it worsens and needs to be pushed back in by hand. Occasionally, it cannot be pushed back by hand and need urgent medical attention. External prolapse is usually associated with pain, bleeding, passage of mucus and faecal incontinence.

Internal prolapse usually presents with symptoms of faecal incontinence and constipation. These symptoms include urgency, faecal incontinence, difficulty defecation and incomplete emptying.

Diagnosis

External prolapse is diagnosed by your doctor with inspection during straining. If prolapse is suspected but cannot be reproduced during doctor examination or an internal prolapse is suspected, a special x-ray called defecating proctogram can be used to diagnose prolapse. Other investigations that can be done include a colonoscopy, anorectal physiology, and examination under anaesthesia

Treatment

External prolapse requires surgical intervention.

Internal prolapse is initially managed non-operatively with laxatives and pelvic floor muscle training. If symptoms persist then surgery may be required.

Rectal prolapse can be repaired via the abdomen or the anus. Abdominal operations involve reducing the prolapse and securing the rectum to the sacrum (the lower spine) usually using a mesh.