Rectal Prolapse

Background:

-Rectal mucosa protruding through the external anal sphincter
-Typically rectal prolapse is a symptom of a predisposing condition, esp if >age 4
-Highest incidence in the first year of life, esp if self limited

Types:

Type I - False procidentia, protrusion of mucosa only, usually <2cm. Produces radial folds at the anal verge
Type II - True procidentia, complete/full thickness prolapse. Produces concentric folds in prolapsed mucosa.

Type II, 1st degree - Includes mucocutaneous junction. Length of protrusion >5cm
Type II, 2nd degree - Does not include mucocutaneous junction 2-5cm
Type II, 3rd degree - Internal, occult; not through anal verge

Predisposing conditions

Increased intrabdominal pressure (e.g. constipation, cough, vomiting 55-65%)
Diarrheal disease 7%
Cystic fibrosis 3%
Malnutrition
Pelvic floor weakness (neuro d/o or postsurgical changes) 10%
Idiopathic/other 20%

Specific Diagnoses include: Chronic constipation, toilet training, coughing, vomiting, straining with urination, abdominal tumors, Diarrhea from infection, parasites, CF, Malnutrition (hypoproteinemia causing mucosal edema), myelomeningocele, tethered cord, spinal cord injury, surgery/postsurgical changes

Other : Polyps, lymphoid hyperplasia, neoplasm, solitary rectal ulcers, Ehlers-Danlos, Williams, Congenital hypothyroidism, anal penetration/sexual abuse

Diagnosis

-Typically clinical or from history. In cases where surgical intervention is planned, fluoroscopic defecography or MRI might guide treatment.

Always consider the following in the differential of rectal prolapse:

Ileocecal intussusception
Rectal hemorrhoids
Prolapsing rectal polyp

Differentiate polyps and hemorrhoids from rectal prolapse by noting that polyps and hemorrhoids do not involve the entire rectal mucosa and do not have a hole in the middle

Management

-Manual reduction if spontaneous reduction does not occur
-Prolonged prolapse will lead to greater irritation, edema, bleeding, and pain making reduction more difficult

Manual reduction

Try to reduce within 5-15min
Using gloves and lube, apply gentle but firm persistent pressure to the prolapsed mucosa
DRE can ensure complete reduction
Use dressing or tape x 2-4hrs to maintain reduction if prolapse re-occurs following reduction (can tape together buttocks if needed)
If unable to reduce manually, apply 1/2 cup of sugar

Treat underlying cause: i.e. optimizing pancreatic enzymes in cystic fibrosis
In cases of constipation, stool softener and stimulant laxatives. (in one study only 6% of patients receiving laxatives required surgical intervention)

If manual reduction fails or prolapse is recurrent, refer for surgical evaluation

Complications

Solitary rectal ulcer syndrome occurs rarely in cases of chronic rectal prolapse. Presents with rectal bleeding, pain, and passing mucous. Endoscopy reveals areas of necrosis and ulceration.
Inflammatory cloacogenic polyps usually 1cm formation at the junction of the squamous anal epithelium and the columnar rectal epithelium.

References:

Siafakas C, Vottler TP, Andersen JM. Rectal prolapse in pediatrics. Clin Pediatr (Phila). 1999 Feb;38(2):63-72. doi: 10.1177/000992289903800201. PMID: 10047938

Cares K, Klein M, Thomas R, El-Baba M. Rectal Prolapse in Children: An Update to Causes, Clinical Presentation, and Management. J Pediatr Gastroenterol Nutr 2020; 70:243