Rectal Prolapse

Rectal prolapse is the protrusion of either the rectal mucosa or the entire wall of the rectum. Partial prolapse involves only the mucosa and usually only protrudes by a few centimetres. Complete prolapse involves all layers of the rectal wall.

• May occur with bowel movements or independently. In the elderly, initially only occurs with defaecation and then retracts spontaneously.
• Later may occur merely on standing thus interfering with patient's quality of life.¹

• Uncommon, but the true incidence is unknown because of under-reporting, especially in the elderly population.
• Mainly occurs in the elderly and children. Complete prolapse is most common in elderly females.
• In children, rectal prolapse occurs most often in patients younger than 4 years, and especially in the first year of life.
• Often associated with long-standing constipation. Other predisposing conditions include chronic straining during defaecation, pregnancy, previous surgery, psychiatric disease and neurological disease.
• In children it may be associated with cystic fibrosis, Ehlers-Danlos syndrome, Hirschsprung disease, congenital megacolon, malnutrition and polyps.

• Mass protruding through the anus: initially only after a bowel movement and usually retracts when the patient stands up. Later the mass protrudes more often, especially with straining and Valsalva manoeuvres such as sneezing or coughing. Finally, the rectum prolapses with daily activities such as walking and may progress to continual prolapse. Patients may have to manually replace it.
• Pain and faecal incontinence may occur.
• If seen on examination, the protruding mass should show concentric rings of mucosa, which are classic signs of rectal prolapse.

• Rectal prolapse must be differentiated from prolapse of an intussusception or a rectal polyp.
• Can usually differentiate a rectal prolapse from a haemorrhoid by the presence of symmetrical circumferential folds occurring with a rectal prolapse.

• Barium enema: Evaluate the entire colon prior to surgery for rectal prolapse to exclude any other colonic lesions that should be simultaneously addressed. Evaluation can be accomplished by colonoscopy or barium enema. Barium enema is a better indicator of the redundancy of the colon.
• Other investigations to assess underlying conditions include stool microscopy and cultures for gastrointestinal infection and sweat test for cystic fibrosis
• In cases of small prolapse, it is sometimes difficult to distinguish between mucosal and full-thickness rectal prolapse. If these cannot be clinically distinguished, a defaecogram may be of help in differentiating these two conditions.
• A defaecogram is unnecessary in the presence of an obvious rectal prolapse.
• Anal rectal manometry is sometimes used to evaluate the anal sphincter muscles. In almost all patients, the results show a decrease in resting pressure in the internal sphincter and an absence of the anorectal inhibitory reflex. The significance of these results is unclear, and most surgeons do not use this test.
• Rigid proctosigmoidoscopy should be performed to assess the rectum for additional lesions, especially solitary rectal ulcers. These ulcers are present in about 10-25% of patients with either internal or full-thickness prolapse.

10% to 25% of affected adult women also have uterine or bladder prolapse, and 35% may have an associated cystocele.

Non-Drug

• Children: gently replace using water-soluble lubricant. Advise parents on need for high fibre diet and inadvisability of straining on stool. A mild laxative may be required, and very occasionally a submucosal injection of a sclerosant.
• Elderly - often well tolerated and concealed with patient manually reducing prolapse. In those unfit for surgery, a subcutaneous circumanal rubber ring may be fitted. However, this often fails either because it is too tight or too loose resulting in constipation or recurrent prolapse.

Surgical

• Partial prolapse often responds to conservative measures but occasionally requires excision of prolapsed mucosa.
• Complete prolapse is treated by abdominal rectopexy.
• If occurs on standing or incontinence develops, most common surgical repair is Delorne's operation which involves excision of the rectum and sigmoid colon via the perineum together with anastomosis of the colon to the anus². Altemierer's procedure is an alternative perineal procedure popular in the USA³.
• Two abdominal operations are suture fixation rectopexy and resection rectopexy. In these the rectum is mobilised and the mesorectum sutured to the sacral promontory and the presacral fascia. In resection rectopexy, additionally a sigmoid colectomy is performed. Laparoscopic repair under study.⁴

• Ulceration of mucosa
• Frequent recurrence despite surgical correction. Abdominal rectopexy occasionally causes incontinence.

• Approximately 10% of patients who experience rectal prolapse as children continue to experience it in their adult lives.
• Approximately 90% of children aged 9 months to 3 years experiencing rectal prolapse respond to conservative management by age 6 years.
• For children older than 4 years who first experience prolapse, a much lower rate of spontaneous resolution exists.