At a glance
When tissue protrudes from the anus, the key distinction is what is prolapsing. Mucosal prolapse involves only the inner lining of the rectum. Full-thickness prolapse involves the entire rectal wall. The distinction matters because it affects the likely course, the treatment options, and the expected outcomes.
Mucosal prolapse
What it is
The rectal mucosa — the inner lining of the rectum — protrudes through the anus without the deeper muscular layers being involved. It is similar in some ways to prolapsing internal hemorrhoids.
What it looks like
- A smaller protrusion than full-thickness prolapse
- Radial folds — the folds in the tissue run outward from the centre, like spokes of a wheel
- Typically pink or reddish mucosa
- Usually occurs during straining and may return spontaneously or with gentle pressure
- Most visible during or immediately after a bowel movement
Symptoms
- Feeling of tissue protruding during bowel movements
- Mucous discharge
- Spotting of bright red blood
- A sense of incomplete evacuation
- Mild discomfort or irritation
Causes
- Straining — chronic constipation and straining weaken the mucosal attachments
- Hemorrhoidal disease — there is overlap between mucosal prolapse and prolapsing internal hemorrhoids
- Weakened pelvic floor — reduced support for the rectal structures
Treatment
Mucosal prolapse can often be managed conservatively or with minor procedures:
- Stool management — reducing straining is the foundation
- Pelvic floor exercises — strengthening the support structures
- Banding — rubber band ligation of the prolapsing mucosa
- Sclerotherapy — injection to reduce and fix the mucosa in place
- Stapled procedure — for more significant mucosal prolapse
Full-thickness rectal prolapse
What it is
The entire wall of the rectum — mucosa, muscle layers, and outer covering — telescopes through the anus. The rectum essentially turns inside out.
What it looks like
- A larger protrusion than mucosal prolapse, often several centimetres
- Concentric folds — the folds run in circular rings around the protrusion (not radial)
- The tissue may be darker red or purple due to the deeper tissue involvement
- In early stages, it may only appear with straining. In advanced cases, it may be present when standing or walking
- The surface may have a sulcus (groove) between the prolapsed rectum and the anal canal
Symptoms
- Visible protrusion of tissue, sometimes significant
- Difficulty with bowel control — faecal incontinence is common
- Mucous discharge
- Bleeding
- A persistent feeling of incomplete evacuation
- Difficulty maintaining hygiene
- Social and emotional impact
Causes
- Weakened pelvic floor and rectal support structures — the most common underlying factor
- Chronic straining — prolonged increased intra-abdominal pressure
- Neurological conditions — affecting pelvic nerve function
- Previous surgery — in some cases
- More common in older adults, particularly women
Treatment
Full-thickness prolapse generally requires surgical repair:
Abdominal approaches:
- Rectopexy — the rectum is lifted back into position and fixed in place, sometimes with mesh
- Laparoscopic rectopexy — the same procedure done through keyhole surgery
- Suitable for patients fit enough for abdominal surgery
Perineal approaches:
- Delorme’s procedure — the prolapsed mucosa is removed and the muscle is plicated
- Altemeier’s procedure — the prolapsed rectum is excised through the perineum
- Often used for older or less fit patients
The choice of procedure depends on the patient’s overall health, the extent of the prolapse, and the surgeon’s expertise.
How to tell the difference
The distinction between mucosal and full-thickness prolapse can sometimes be made on examination, but it is not always obvious:
- Concentric folds = more likely full-thickness
- Radial folds = more likely mucosal
- Length of protrusion — full-thickness tends to be longer
- Examination under anaesthesia may be needed for a definitive assessment
- Imaging (defaecating proctogram or MRI) can help clarify the diagnosis
If you are experiencing rectal prolapse of any kind, assessment by a specialist is important. The type of prolapse determines the appropriate management, and getting the diagnosis right is the first step.