Intussusception

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Referral

Definition

Intussusception is a condition in which a segment of the bowel telescopes into an adjacent section, leading to bowel obstruction and compromised blood supply.

Aetiology

Intussusception is most common in infants and young children but can also occur in adults.

  • Idiopathic (most common in children): no clear underlying cause, often occurs after viral infections.
  • Pathological lead points (more common in adults):
    • Meckel’s diverticulum.
    • Intestinal polyps or tumours.
    • Hypertrophied Peyer’s patches (following viral infections).
    • Henoch-Schönlein purpura (HSP).
    • Cystic fibrosis (thickened mucus can lead to obstruction).

Pathophysiology

  • The proximal bowel segment telescopes into the distal segment.
  • Obstruction leads to venous congestion and oedema.
  • Prolonged intussusception causes reduced arterial blood flow, ischaemia, necrosis, and potential perforation.

Risk factors

  • Age 3 months to 3 years (peak incidence at 6–12 months).
  • Recent viral infections (e.g., adenovirus, rotavirus).
  • Male gender (higher prevalence).
  • Congenital malformations (e.g., Meckel’s diverticulum).
  • Inflammatory conditions (e.g., Henoch-Schönlein purpura).
  • Postoperative adhesions.

Signs and symptoms

Symptoms:

  • Intermittent episodes of severe, colicky abdominal pain.
  • Drawing knees to chest (pain relief posture in infants).
  • Vomiting (can be bilious if obstruction is present).
  • Blood-stained, “red currant jelly” stool (late sign, due to bowel ischaemia).

Signs:

  • Pallor and lethargy between pain episodes.
  • Palpable “sausage-shaped” mass in the right upper quadrant.
  • Abdominal distension and tenderness.
  • Signs of shock if perforation occurs (tachycardia, hypotension, cool peripheries).

Investigations

  • Abdominal ultrasound (first-line): common finding of target or "donut sign" in transverse view and "pseudokidney sign" in longitudinal view.
  • X-ray: may show dilated bowel loops and air-fluid levels.
  • Contrast enema: can be diagnostic and therapeutic.
  • Blood tests:
    • Raised white cell count and CRP (suggests inflammation or infection).
    • Lactate levels (may be raised in bowel ischaemia).

Management

1. Initial Resuscitation:

  • Nil by mouth: prevents further bowel distension.
  • IV fluids: to correct dehydration.
  • Nasogastric (NG) tube: for decompression if vomiting is present.
  • Analgesia: paracetamol or opioids as needed.

2. Non-Surgical Reduction (Preferred First-Line):

  • Air or contrast enema: performed under radiological guidance to reduce the intussusception.
  • Success rate >75% in children without complications.
  • Contraindicated if perforation or peritonitis is present.

3. Surgical Management (Indications):

  • Perforation, peritonitis, or failed enema reduction.
  • Identified lead point (e.g., Meckel’s diverticulum, tumour).
  • Recurrent intussusception.
  • Procedure: laparoscopic or open surgical reduction, with resection if necrosis is present.

Referral

  • Emergency/hospital paediatric surgical referral: all suspected cases require urgent review.
GastroenterologymypanotesIntussusception