Rectal prolapse can be divided into complete rectal prolapse, partial rectal prolapse, internal rectal prolapse, rectocele or mucosal prolapse. Other related terminologies include intussception or procidentia. Complete rectal prolapse or external rectal prolapse is the prolapse of rectal wall to a degree where it protrudes out of the anus and is visible outside.
Rectal prolapse may result in mucous discharge, rectal bleeding, degrees of faecal incontinence and obstructed defecation symptoms.
Rectal prolapse can occur at any age and in any gender but is more common in elderly women. Most external prolpases have to be treated with surgery though surgical procedures may vary. Internal prolapses or rectoceles are often treated conservatively at first and a small proportion go on to need surgery for correction.
External (complete) rectal prolapse (rectal procidentia, full thickness rectal prolapse, external rectal prolapse) is a full thickness, circumferential, true intussusception of the rectal wall which protrudes from the anus and is visible externally.
Internal rectal intussusception (occult rectal prolapse, internal procidentia) can be defined as a infolding of the upper rectal (or lower sigmoid) wall that can occur during defecation. This infolding is perhaps best visualised as folding a sock inside out creating “a tube within a tube”
Mucosal prolapse (partial rectal mucosal prolapse) refers to prolapse of the lining of the lower bowel due to loosening of the submucosal attachments to the muscularis propria of the rectal wall. It can be easily confused with prolapsed (3rd or 4th degree) hemorrhoids.
Solitary rectal ulcer syndrome (SRUS, solitary rectal ulcer, SRU) occurs with internal rectal intussusception and is part of the spectrum of rectal prolapse conditions. It describes ulceration of the rectal lining caused by repeated frictional damage as the intussusception is forced into the anal canal during straining. SRUS can be considered a consequence of internal intussusception, which can be demonstrated in majority of cases.
Patients may have associated gynecological or urological conditions which may require multidisciplinary management. History of constipation is important because some of the operations may worsen constipation. Fecal incontinence may also influence the choice of management.
Investigations
Patients need a full clinical examination and investigations including flexible sigmoidoscopy or colonoscopy, proctogram, anorectal manometry and physiology studies.
Treatment
The only potentially curative treatment for complete rectal prolapse is surgery. Various surgical options exist.
Dietary adjustments to reduce constipation and straining may help to some extent especially in patients unfit for surgery but prolapse symptoms are difficult to control with conservative measures alone.
Conservative treatment has a more significant role in other forms of prolapse. Internal rectal prolaspe, intussception or rectocele- all may benefit from dietary advice, biofeedback and pelvic floor physiotherapy. A small proportion of patient with symptoms due to these forms of prolpase need surgery to correct the anatomical abnormality.
Many surgical operations are available and can broadly be divided into perineal and abdominal operations. Surgical approach and choice of operation depends on the exact nature of symptoms, patient fitness and patient choice. There are many perineal procedures depending on the symptoms and anatomy and include mucopexy, mucosal excision, STARR procedure, delormes procedure, altemier’s procedure etc. Abdominal procedures include posterior, ventral rectopexy or resection rectopexy. These are most often performed laparoscopically.