Discussion
Rectal prolapse has an incidence of 0.5% and is more commonly seen in the elderly3. Risk factors include female gender, age over 40, multiparity, vaginal delivery, prior pelvic surgery, chronic straining, chronic diarrhoea or constipation, cystic fibrosis, dementia or stroke, pelvic floor dysfunction and anatomical defects such as anterior or posterior vaginal wall prolapse1.
Patients present with abdominal discomfort, incomplete bowel evacuation and mucus and/or stool discharge, altered bowel habits, faecal incontinence and a prolapsing mass through the anus that may reduce spontaneously or require manual reduction1,3.
It is associated with a number of anatomical anomalies including diastasis of the levator ani, a deep cul-de-sac, a redundant sigmoid colon, a patulous anal sphincter, and a loss of rectal sacral attachments3.
Initial assessment should include a complete history and physical examination3. The clinician should review the patient’s diet, fiber intake, fluid intake, and use of medication that may contribute to constipation, symptoms of concomitant uterine or vaginal prolapse and urinary incontinence1, and underlying conditions3.
On examination, the concentric rings of the rectum protruding through the anus are the hallmark of rectal prolapse1. Digital rectal examination may find a patulous anus, poor sphincter tone, mass and  concomitant pelvic floor pathology1.
Defecography with fluoroscopy or MRI is helpful if the prolapse is unable to be reproduced on examination and may reveal concomitant pelvic floor prolapse1. Those with pelvic floor prolapse may benefit from urodynamics3. A colonoscopy should be considered to look for an underlying neoplasm3. Anal physiologic testing may identify associated functional disorders such as constipation or fecal incontinence3.
The general consensus in the literature is that rectal prolapse cannot be corrected non-surgically with medical therapy alone3. Medical therapy to date is limited to adequate fluid and fibres, stool softeners to treat constipation and skin care to avoid maceration1,3; the use of anal plugs have been described4. These are considered palliative interventions that do not address the prolapse itself but may improve the patient’s quality of life3.
Surgical repair of rectal prolapse is the treatment of choice1, either transabdominal or perineal. There is no consensus on the optimal surgical approach in terms of recurrence rate or bowel function1. Choice of surgery depends on the patient’s status, age, baseline bowel function, surgeon’s experience and preference1.
Abdominal procedures have higher mortality and morbidity rates compared to perineal procedures2. The mortality rates for abdominal procedures is 0 to 7 percent and morbidity rates is 0 to 52 percent2. The most common major complications include pelvic infection, hematomas, fistulas, stenosis and obstructed defecation2. As such, patients with poorer medico-surgical co-morbidities may be more suitable for perineal repairs2.
Although abdominal procedures have lower recurrence rates, perineal procedures have fewer risks and complications than abdominal procedures with reported mortality 0 to 4 percent and morbidity rates less than 20 percent2. Complications after a perineal repair include bleeding, pelvic infection and faecal leakage2.
After surgery, symptoms of faecal incontinence generally improve; symptoms of constipation generally improve with perineal procedures but may improve or worsen with abdominal procedures2. Patients undergoing perineal repair procedures show an improvement in constipation ranging from 13 to 100 percent2.
Vaginal pessaries are commonly used in gynaecological practice as a non-surgical option for the treatment of vaginal pelvic organ prolapse (POP) and stress urinary incontinence5.
There are reports of intravaginal devices for faecal incontinence treatment8. This ‘vaginal bowel-control system’ is described as a vaginal silicone-coated stainless steel base with a posterior balloon that is pressure-regulated pump8. The pump is deflated for a bowel movement and inflated to prevent incontinence; this acts on the distal rectum to allow the patient to control her bowel motions8. Similar to the vaginal pessary for prolapse, not all women could be successfully fit as a result of discomfort, vaginal dimensions or exclusion criteria8.
Vaginal pessaries are generally made of medical grade silicone that come in a range of shapes and sizes to support the pelvic organs, with the space occupying type being more suitable for a larger prolapse5. There is no robust evidence for the use of one type of pessary over another, so similar to the pessary fitting for POP, choice of vaginal pessary for rectal prolapse requires some trial and error5. When choosing an initial pessary size, a pelvic examination is required to assess the length of the vagina from the posterior fornix to the pubic symphysis, and to assess the vaginal width by spreading the index and middle fingers horizontally at the level of cervix or vaginal vault5. Support pessaries lie along the vaginal axis; the posterior component sits in the posterior vaginal fornix and the anterior component sits under the symphysis pubis5,6. An appropriate size is achieved when the patient’s symptoms are relieved, they are able to void and defecate, the pessary remains in situ with activities of daily living, is comfortable for the patient and allows the patient the preservation of sexual intercourse should this be their wish5.
Figure 2 shows a rectocele and intussusception before and after a vaginal pessary is placed in situ, with a reduction of the rectal prolapse possibly by elevating and supporting the previous Delormes “doughnut”.
When counselling of patients on use of the vaginal pessary for rectal prolapse, potential complications need to be discussed5. Side effects include vaginal discharge, ulcerations, bleeding, pain, vaginal and urinary tract infections, urinary retention, faecal impaction, interference with sexual intercourse, de novo (occult) SUI and pessary expulsion5,6. A forgotten pessary can result in erosion into the bowel, bladder or vaginal wall and fistula formation5.
Once the pessary is inserted, the woman is asked to strain and cough, ambulate and void and strain while sitting on a toilet6. This determines that the pessary will not be expelled and that the patient can void when she returns home5,6. Vaginal estrogen should be prescribed for postmenopausal women to reduce the risk of vaginal erosion5. There is a need for regular follow-up every 3-6 months to change the pessary, assess for side effects and examine the vagina for erosion5.
The success rate, that is the continued use of the pessary in women for POP, is around 80% at 2-3 months and 60% at 6-12 months5,6. 50 to 60% of women who trial a pessary for POP continue to use them for a further one to two years6,7. Long term data on success rate of the use of the pessary for rectal procidentia requires larger trials.