Introduction
A rectal prolapse is the protrusion of mucosal or full-thickness layer of rectal tissue out of the anus. It is a relatively uncommon condition, affecting about 2.5 per 100 000 individuals each year in the UK, mainly affecting older females.
There are two main types* of rectal prolapse:
- Partial thickness – the rectal mucosa protrudes out of the anus
- Full thickness – the rectal wall protrudes out the anus
In this article, we shall look at the pathophysiology, clinical features, and management of rectal prolapse.
*Internal intussusception is the prolapse of the rectum into the distal rectum or anal canal but without its protrusion outside of the anus
Pathophysiology
The current theories surrounding full prolapse suggest that is a form of sliding hernia, through a defect of the fascia of the pelvic region. This may be caused by chronic straining secondary to constipation, a chronic cough, or from multiple vaginal deliveries.
In contrast, partial thickness prolapses are associated with the loosening and stretching of the connective tissue that attaches the rectal mucosa to the remainder of the rectal wall. This often occurs in conjunction with long standing haemorrhoidal disease.
Figure 1 – Schematic demonstrating a rectal prolapse
Risk Factors
The main risk factors for rectal prolapse are increasing age, female gender, multiple deliveries, straining, anorexia, and previous traumatic vaginal delivery.
Clinical Features
Patients with a rectal prolapse will typically present with rectal mucus discharge, faecal incontinence, per rectum bleeding, or with visible ulceration.
Full thickness prolapses (Fig. 2) will begin internally and thus can initially present with a sensation of rectal fullness, tenesmus, or repeated defecation.
On examination, the prolapse may not always be evident, but can be identified by asking the patient to strain. A digital rectal examination should be performed, often on which a weakened anal sphincter is identified.
For a suspected internal prolapse, defecating proctography and examination under anaesthesia may be the only means to diagnose clinically.
Figure 2 – Appearances of a full thickness rectal prolapse
Management
Conservative management of rectal prolapse is more common in those unfit for surgery, with minimal symptoms, or in children (as most prolapses in children will resolve spontaneously).
Initial management often involves increasing dietary fibre and fluid intake. Minor mucosal prolapses may be banded in clinic, although this is prone to recurrence.
Surgical Management
Surgical repair is the only definitive management. The mainstay of treatments is between the abdominal approach and the perineal approach:
- Perineal approach
- The two more commonly performed operations are the Delormes operation (the prolapsed lining of the rectal mucosa is removed and the underlying muscle reinforced with plicated sutures) and the Altemeier’s operation (resection of the redundant prolapsed bowel to restore the original anatomy)
- Abdominal approach
- Performed laparoscopically (most common), robotically, or open, the procedure will involve a rectopexy, whereby the rectum is mobilised and fixed onto the sacral prominence via sutures or mesh
Overall, whilst studies have shown no difference in the post-operative outcomes between abdominal and perineal procedures, the perineal procedures are preferred in older patients as they are considered safer operations.
Key Points
- Rectal prolapse can be either partial or full thickness prolapse
- Symptoms may include rectal mucus discharge, faecal soiling, or rectal bleeding
- Definitive management is via surgical repair, either by an abdominal or perineal approach
