Rectal Mucosal Prolapse

Rectal mucosal prolapse is protrusion of redundant rectal or anal mucosa through the anal canal without the full thickness of the rectal wall, often as a component of internal rectal intussusception or complete prolapse.

• Causes: chronic straining, constipation, pelvic floor weakness, haemorrhoidal disease, childbirth, previous anorectal surgery, chronic diarrhoea, neurological disease, cystic fibrosis (children), schistosomiasis and parasitic infestation (Trichuris trichiura heavy burden in children).
• It occurs in children under 4 years, young adults and the elderly; women are more affected.

Protrusion with defecation that reduces spontaneously or manually, mucus discharge, soiling, rectal bleeding, tenesmus, sense of incomplete evacuation, pruritus ani and difficulty with hygiene.

• Radial folds (mucosal prolapse) differ from concentric folds (full thickness prolapse) on examination.
• Differential diagnosis: full thickness rectal prolapse, prolapsed haemorrhoids, rectal polyp, anal skin tags, solitary rectal ulcer, rectal tumour, intussusception, perianal warts.
• Complications: incarceration, strangulation, ulceration and bleeding, faecal incontinence, anaemia, pruritus, progression to full thickness prolapse and secondary infection.

Clinical, with examination during straining on a toilet or in squatting.

• Proctoscopy and flexible sigmoidoscopy to exclude polyps, tumours, colitis.
• Defecography (barium or MR) or dynamic MRI to show intussusception and its depth; anorectal manometry and endoanal ultrasound for incontinence.
• Stool microscopy for Trichuris and Schistosoma in endemic settings; sweat chloride test in children with cystic fibrosis suspicion.

Supportive: treat constipation and straining (fibre 25 to 30 g daily, fluids, toilet posture), limit toilet time, manual reduction with lubricant, pelvic floor exercises.

Pharmacological

• Macrogol 17 g daily or lactulose 15 to 30 mL twice daily.
• Parasites: albendazole 400 mg daily for 3 days for Trichuris (children 1 year and over); praziquantel 40 mg/kg single dose for schistosomiasis.
• Haemorrhoid-related prolapse: topical lidocaine 2 percent and flavonoid therapy such as micronised purified flavonoid fraction 1000 mg daily for symptom relief.
• Child with incarcerated prolapse: apply granulated sugar or hypertonic saline to reduce oedema before reduction.

Procedures

• Rubber band ligation of redundant mucosa or sclerotherapy (phenol in oil 5 percent or polidocanol 3 percent injected submucosally) for mild disease.
• Excisional mucosal resection (Delorme procedure), stapled transanal rectal resection or transanal haemorrhoidectomy for symptomatic mucosal prolapse; perianal encirclement is rarely used.
• Laparoscopic ventral mesh rectopexy for associated internal intussusception with obstructed defecation.
• Biofeedback for dyssynergia.

Special groups: children (conservative therapy, sclerosant injection if persistent), elderly (perineal procedures under regional anaesthesia), pregnancy (conservative).

Red flags: irreducible prolapse with pain and dusky mucosa (strangulation), heavy bleeding, ulcer, suspected malignancy, faecal incontinence.

Follow-up: review at 6 weeks; maintain stool consistency; reassess in 3 months for recurrence.