Definition: the mucosa (partial/ type 1), or all layers (complete/ type 2- more common) protrude through the anus.
Aetiology/ risk factors:
Incomplete prolapse- seen in both adults and children and associated with excessive straining, constipation and haemorrhoids.
Complete prolapse- occurs mainly in adults, and associated with weak pelvis and anal musculature. Constipation, advanced age, chronic straining, sphincter paralysis, neurological conditions e.g. MS, cystic fibrosis in children.
Epidemiology: relatively common
Peak incidence in children < 3 years and elderly (6x more in elderly females)
-protruding anal mass, may require digital replacement
-faecal incontinence (in 75%)
-PR mucus or bleeding
-may present as emergency, with irreducible or strangulated prolapse
-prolapse may be seen on straining
-may be ulcerated or necrosed if vascular supply compromised
-decreased anal sphincter tone (on PR exam)
-defecating proctogram (mechanics of a patient’s defecation are visualized in real time using a fluoroscope)
-anal sphincter manometry (used to measure contractility in the anus), pudendal nerve studies (main nerve of the perineum)
-sweat chloride test for cystic fibrosis- in children, ∼10% will have CF
Conservative– treat constipation with laxatives, increase fibre in diet (usually sufficient in children)
-acute prolapse may be manually reduced after adequate analgesia
-if bowel is gangrenous = excision by rectosigmoidectomy
Incomplete prolapse = submucosal injection sclerotherapy with phenol in oil, mucosal banding or haemorrhoidectomy
Abdominal approach- fix rectum to sacrum (rectopexy) +/- mesh insertion +/- rectosigmoidectomy.
Perineal approach- Delorme’s procedure (resect close to dentate line and suture mucosal boundaries), anal encirclement with a Thiersch wire.
-rarely, strangulation and necrosis of prolapsed bowel
Prognosis: spontaneous resolution usually occurs in children. Generally good in adults with appropriate treatment, although there is a 15% recurrence rate.
References: Cheese & Onion, Rapid Surgery