GI

Rectal Prolapse

Definition

  1. Rectal prolapse is defined as an extrusion of some or all of the rectal mucosa through the external anal sphincter. It usually occurs between 1-4 years of age, with the highest incidence in the first year of life.
  2. There are two types of rectal prolapse
    1.  Type 1 (false procidentia, partial, mucosal prolapse) involves protrusion of the mucosa only.
    2. Type 2 (true procidentia, complete prolapse) involves a full thickness extrusion of the rectal wall.
  3. Type 2, or complete prolapses, are divided according to severity:
    1. 1st degree prolapse includes the mucocutaneous junction, with length of the protrusion from the anal verge > 5 cm.
    2. 2nd degree prolapse does not involve the mucocutaneous junction, with protrusion from the anal verge from 2 - 5 cm.
    3. 3rd degree prolapse is internal and does not pass through the anal verge.

 

Pathogenesis

Rectal prolapse is thought to be caused by circumferential intussusception of the upper rectum and rectosigmoid colon.

 

Etiology

  1. Most are idiopathic
  2. Increased intra-abdominal pressure
    1. Constipation
    2. Coughing- paroxysmal or chronic coughs
    3. Chronic vomiting
    4. Straining during urination secondary to obstruction
  3. Diarrheal diseases
    1. Acute infections
    2. Chronic diarrhea associated with malabsorption syndromes, such as celiac disease
  4. Parasitic infestations (Ascaris and trichuriasis)
  5. Neoplasms of rectal area
  6. Malnutrition states (most common cause worldwide)- hypoproteinemia leads to mucosal edema and decreased immune function leads to increased susceptibility to enteric infections.
  7. Cystic Fibrosis- There is a 25% incidence in CF patients and CF accounts for about 10% of all prolapses. This incidence decreases if the patient is receiving pancreatic enzyme supplementation. Prolapse may be the presenting symptom and may be secondary to malnutrition, chronic diarrhea and cough.
  8. Neuromuscular syndromes including meningomyeloceles, tethered cords.
  9. Ehler-Danlos, Hirschsprung's disease, hypothyroidism and anal sex

 

Diagnosis

  1. Usually presents as a painless, dark red mass at the anal verge, with or without mucous.  There may be slight blood staining of diaper or underwear. This is a source of great parental anxiety and usually by the time the family has reached the doctor, the prolapse has reduced itself. Parents usually discover the extrusion while the child is defecating during potty training. Examining the child in the squatting position or asking them to strain may demonstrate the prolapse in the office if it has spontaneously resolved upon presentation. Palpation of the prolapsed mucosa can distinguish a Type I from a Type 2 prolapse.
  2. 3rd degree rectal prolapse (occult prolapse) is less obvious, presenting as tenesmus and anorectal pain with passage of blood and mucous. Diagnosis may require sigmoidoscopy.

 

Differential Diagnosis

  1. Protrusion of rectal polyp
  2. Hemorrhoidal tissue
  3. Ileocecal intussusception

 

Evaluation and Treatment

In general, treatment focuses on treating the condition predisposing the child to rectal prolapse, if known.

  1. If the prolapsed tissue does not spontaneously reduce, manually do so as soon as possible before the tissue becomes edematous and ulcerated. 
  2. After reducing, do a rectal examination to ensure that it is reduced. 
  3. Workup should include a sweat test to rule out CF and a complete history to diagnose other causes including mal-absorption syndromes, parasitic exposure, chronic constipation, potty training issues, and neuromuscular diseases
  4. Teach parents how to reduce a prolapse at home. Provide gloves and Vaseline
  5. Reduce the problem of constipation with stool softeners and laxatives, and have the child defecate with feet on the ground.
  6. Surgery may be necessary but is associated with complications. It is most likely necessary when an underlying neurologic condition exists.

 

Prognosis

  1. The prognosis for rectal prolapse is good.  Approximately 90 % of children who develop it between the ages of 9 mo. and 3 yrs. respond to conservative measures like manual correction. 
  2. 10 % of children with rectal prolapse have recurrences that persist into adulthood.
  3. Children who present with rectal prolapse after four years of age usually have neurologic or musculoskeletal defects of the pelvis and should be referred early for surgical intervention.

 

References

  1. Groff DB, Nagaraj HS. Rectal prolapse in infants and children. American Journal of Surgery. 1990;160(5):531-2.
  2. Ashcraft, Keith W., et al. Rectal prolapse: 17-year experience with the posterior repair and suspension. Journal of Pediatric Surgery 25.9 (1990): 992-995.
  3. Siafakas, Constantinos, Vottler, Theodore, and Andersen, John. Rectal Prolapse in Pediatrics. Clinical Pediatrics. February 1999
  4. Zempsky WT, Rosenstein BJ. The cause of rectal prolapse in children. American Journal of Diseases of Children. 1988;142(3):338-9.
  5. Shawis, R. Management of rectal prolapse in children. Dis Colon Rectum 48 (2005): 1620-1625.