Rectal Prolapse

Full thickness rectal prolapse is circumferential protrusion of all layers of the rectal wall through the anal canal.

It must be distinguished from mucosal prolapse and prolapsing haemorrhoids, which do not involve the entire bowel wall.

Chronic prolapse progressively stretches the anal sphincter and pelvic nerves and frequently causes faecal incontinence. Constipation and obstructed defaecation may coexist.

Surgery is the definitive treatment.

Patients report a rectal mass appearing during defaecation and eventually during standing, coughing or walking.

Associated symptoms include:

• Faecal incontinence
• Mucus discharge
• Rectal bleeding
• Constipation
• Incomplete evacuation

On examination, full thickness prolapse produces concentric circumferential folds. Prolapsing haemorrhoids produce radial folds.

Assess sphincter tone, pelvic floor function and associated vaginal or pelvic organ prolapse.

Diagnosis is usually clinical. Ask the patient to strain on a commode if prolapse is not visible during routine examination.

Defaecography: useful for occult internal prolapse or associated pelvic floor abnormalities when findings will change surgical planning.

Perform colonoscopy before elective repair when age, screening status or symptoms require exclusion of colorectal pathology.

Conservative measures can improve stool consistency and reduce straining but do not correct established full thickness prolapse.

Abdominal repair

A fit patient generally receives an abdominal rectopexy because durability is usually better than perineal reconstruction.

Options include:

Suture rectopexy: rectal mobilisation followed by fixation to the sacrum.

Ventral mesh rectopexy: limited anterior rectal dissection with ventral fixation, designed to minimise posterior autonomic nerve injury and postoperative constipation.

Resection rectopexy: sigmoid resection combined with rectopexy, particularly useful when prolapse coexists with significant constipation and a redundant sigmoid colon.

Avoid sigmoid resection in patients with major baseline faecal incontinence unless there is a clear indication because bowel frequency may worsen.

Perineal repair

A frail or elderly patient who is a poor candidate for abdominal surgery may undergo a perineal procedure.

Altemeier perineal rectosigmoidectomy removes the prolapsed full thickness rectum and redundant sigmoid through the perineum and creates a coloanal anastomosis. Recurrence is higher than with many abdominal approaches but physiological burden is lower.

Delorme procedure removes prolapsed rectal mucosa and plicates the muscular wall and is most useful for a shorter prolapse.

Incarcerated prolapse

A viable incarcerated prolapse can undergo gentle manual reduction after analgesia. Granulated sugar applied to markedly oedematous prolapsed mucosa can draw out fluid osmotically and facilitate reduction.

Do not repeatedly manipulate dark, ulcerated or clearly ischaemic bowel.

Gangrene, perforation or failed reduction with threatened rectum requires emergency surgery, commonly perineal rectosigmoidectomy in an appropriate patient.

Correct constipation and pelvic floor dysfunction after surgery because persistent straining contributes to recurrence.