Rectal Prolapse

Basics

Description

There are three types of rectal prolapse:

  • Complete: full thickness of rectum prolapses through anus (two layers of rectum with an intervening peritoneal sac, which may contain small bowel)
  • Incomplete/mucosal: prolapse limited to only two layers of mucosa
  • Concealed: internal intussusception of upper rectum into lower, with no extrusion into the anus

Epidemiology

  • Most cases occur in children <4 years of age around time of toilet training; equal incidence in boys and girls
  • In older children and adults, strong (6-fold) female predilection
  • Common in developing countries, perhaps because of poor nutrition and parasitic infection; less common in industrialized countries

Risk Factors

  • Cystic fibrosis (CF)
    • Typically presents between 6 months and 3 years of age in patients with CF
    • Presentation in children with CF >5 years of age is rare.
  • Chronic constipation
    • About 50% of children with chronic constipation will experience prolapse.

Genetics

  • Inheritance patterns depend on associated underlying etiologies.
  • No known inheritance pattern for idiopathic rectal prolapse

Etiology

Exact etiology uncertain

Commonly Associated Conditions

  • Excessive straining with bowel movements from constipation and toilet training (hips and knees flexed) is the most common cause in industrialized countries.
  • Diarrhea; may be more of a cause in tropical and subtropical countries
  • Infections: hookworms and other parasitic infections
  • Malnutrition; can cause loss of the ischiorectal fat pad
  • Complication of past surgery, such as imperforate anus repair
  • Complete prolapse is rare in children, but when it occurs, it may be related to poor fixation of rectum to sacrum and to weak pelvic and anal musculature.
  • CF
  • Ulcerative colitis
  • Hirschsprung disease
  • Ehlers-Danlos syndrome
  • Meningomyelocele
  • Pertussis
  • Rectal polyp
  • Pneumonia
  • Anorexia
  • Rectal neoplasm

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