Intussusception Summary

Definition

  • Telescoping of one portion of intestine into another
  • Most common in children 3 months to 3 years
  • Ileocolonic location most common

Clinical Features

  • Paroxysmal colicky abdominal pain
  • Redcurrant jelly stools
  • Vomiting
  • Sausage-shaped RUQ mass

Diagnosis

  • Ultrasound (first choice)
  • Target/doughnut sign on imaging
  • Contrast enema for diagnosis & treatment

Management

  • Stable patients: nonoperative reduction
  • Unstable patients: surgical intervention
  • Watch for complications

Intussusception: Diagnosis and Management

Medical guidelines for identifying and treating intussusception

Clinical Anatomy

Intussusception is the telescoping of one portion of the intestine (the intussusceptum) into the lumen of the intestine immediately distal to it (the intussuscipiens). The mesentery is dragged alongside the proximal bowel wall into the distal lumen resulting in obstruction of venous return. Oedema, mucosal bleeding, and increased pressure result. If arterial flow becomes compromised, ischaemia, necrosis, and perforation can occur.

Ileocolonic Intussusception

Prolapse of the terminal ileum into the proximal colon is the most common anatomical location for intussusception to occur.

Other Locations

Ileoileal and colocolonic intussusceptions are less common but can also occur.

Intussusception diagram
Schematic representation of intussusception showing telescoping of bowel

Causes

Primary Cause

The aetiology of most cases of intussusception is unclear but is likely to be related to hyperplasia of Peyer's patches and lymphoid tissue in the intestinal wall resulting from antecedent viral infection. These enlarged lymph nodes may act as the lead point in idiopathic intussusception.

Pathological Lead Points

In Older Children & Adults

Intussusception in older children and adults is rare and is almost always caused by a pathological lead point.

Anatomical Abnormalities

Pathological lead points include luminal polyps, malignant tumors (including lymphoma), and benign mass lesions.

Specific Conditions

Meckel's diverticulum, Henoch-Schonlein purpura, and enteric duplication cysts can also serve as lead points.

Clinical Features

Most intussusceptions are seen in children between 3 months and 3 years, most commonly in infants under 1 year of age. Boys are more commonly affected than girls.

Paroxysmal abdominal pain - They may present with paroxysms of colicky abdominal pain and crying (during the attack the child becomes pale, distressed and draws up the legs).
Well between episodes - The child may appear well between paroxysms initially.
Vomiting - There is early vomiting.
Redcurrant jelly stools - So-called redcurrant jelly stools may be passed (which consist of mucus and blood).
Abdominal findings - Abdominal examination may reveal a distended abdomen, a palpable sausage-shaped mass (often in the RUQ) and absence of bowel in the right lower quadrant (Dance's sign).

Differential Diagnosis

Differential Diagnoses

Several conditions can present similarly to intussusception and should be considered in the differential diagnosis.

Appendicitis - Inflammation of the appendix
Gastroenteritis - Inflammation of the stomach and intestines
Urinary tract infection - Infection of the urinary system
Pyloric stenosis - Narrowing of the pylorus

Investigations

The target sign (variants according to appearance or imaging modality include bull's eye sign, doughnut sign, crescent-in-doughnut sign, and multiple concentric ring sign) is a single hypoechoic ring with a hyperechoic centre, indicating that one portion of the bowel has been drawn within the lumen of an adjacent portion.

Abdominal X-ray

Performed as initial investigation if perforation or obstruction is suspected. Plain abdominal films may be normal, or may show the typical target sign.

Ultrasound

If the patient is clinically stable and perforation is not suspected, ultrasonography should be the initial diagnostic test for intussusception. Ultrasound has a reported diagnostic accuracy of up to 100%.

Contrast Enema

A contrast enema (air or contrast reagent) can be performed to diagnose intussusception but is contraindicated in the presence of free intra-abdominal air.

CT Abdomen

Normally not indicated for the evaluation of intussusception. May be used to assess for the presence and identification of a pathological lead point.

Management

Treatment Approach

Management of intussusception depends on the patient's clinical status and presence of complications.

Nonoperative Reduction

Stable patients with a high clinical suspicion and/or radiographic evidence of intussusception and no evidence of bowel perforation should be treated with nonoperative reduction using hydrostatic or pneumatic pressure by contrast enema (air or liquid contrast).

Surgical Treatment

Surgical treatment is indicated as a primary intervention for patients with suspected intussusception who are acutely ill or have evidence of perforation, peritonitis or shock.

Complications

Potential Complications

Intussusception can lead to several serious complications that require prompt recognition and management.

Ischaemia, infarction and necrosis - Due to compromised blood supply
Obstruction - Bowel obstruction from the telescoped segment
Perforation - Bowel wall rupture
Peritonitis - Inflammation of the peritoneum
Sepsis - Systemic infection
Haemorrhage - Bleeding from compromised bowel