Intussusception – Causes, Symptoms, Diagnosis, and Treatment 🩺

Intussusception is a serious medical condition in which a part of the intestine folds into the section next to it, similar to how segments of a telescope slide into each other. This condition is most common in infants and young children, but it can also occur in adults, usually secondary to other gastrointestinal abnormalities. Left untreated, intussusception can lead to bowel obstruction, ischemia, necrosis, and even death. Understanding this condition thoroughly is crucial for both students preparing for medical exams and professionals handling pediatric and emergency cases.

Pathophysiology of Intussusception

In intussusception, the ileum (end portion of the small intestine) telescopes into the cecum (the first part of the large intestine). This leads to a series of pathological events:

1. Mechanical Obstruction – The telescoping creates a blockage, preventing the normal passage of food and stool.

2. Compression of Blood Vessels – The mesentery and blood vessels supplying the bowel are squeezed, reducing circulation.

3. Decreased Blood Flow – Ischemia develops, leading to tissue hypoxia.

4. Bowel Ischemia and Necrosis – Prolonged ischemia causes death of bowel tissue.

5. Rectal Bleeding – Classically, patients pass currant jelly stools, which are stools mixed with blood and mucus.

This cascade explains why intussusception is considered a pediatric emergency that requires prompt recognition and treatment.

Causes of Intussusception

The exact cause of intussusception is not completely understood, but research and clinical observations suggest multiple contributing factors:

1. Idiopathic Cases (Most Common in Children)

Many cases have no identifiable lead point and are thought to be associated with viral infections that cause lymphoid hyperplasia (swelling of Peyer’s patches in the ileum).

2. Lead Point Lesions (More common in older children and adults):

• Meckel’s diverticulum
• Intestinal polyps
• Tumors (benign or malignant)
• Foreign bodies
• Post-operative adhesions

3. Viral Infections

Some cases are associated with adenovirus or rotavirus, which lead to inflammation and swelling in the intestinal wall.

Signs and Symptoms of Intussusception

The clinical presentation of intussusception is often intermittent and misleading, making diagnosis tricky. Symptoms include:

Intermittent abdominal pain and cramping – The child may cry inconsolably and draw their knees to the chest.

Vomiting and diarrhea – Initially non-bilious but may progress to bilious vomiting.

Bloody stools (Currant Jelly Stools) – Mixture of mucus and blood, a classical but late sign.

Lethargy and shock – Advanced cases may present with extreme tiredness due to dehydration and shock.

Palpable mass – A “sausage-shaped” mass may be felt in the upper mid-abdomen during examination.

Because symptoms can overlap with other gastrointestinal conditions like gastroenteritis, clinical suspicion and diagnostic imaging are key.

Diagnosis of Intussusception

Diagnosis is made using a combination of clinical features and imaging:

Abdominal Ultrasound – Gold standard, showing the “target sign” or “donut sign” representing concentric layers of the bowel.

X-ray Abdomen – May show signs of intestinal obstruction.

Contrast Enema (Air or Barium Enema) – Diagnostic and therapeutic, both confirming the diagnosis and reducing the intussusception in many cases.

Treatment of Intussusception

Prompt treatment is essential to avoid ischemia, perforation, and peritonitis. Management includes:

Conservative/Non-Surgical Treatment

Air or Barium Enema Reduction – First-line treatment in stable patients; serves both diagnostic and therapeutic purposes.

IV Fluids – For rehydration and correction of electrolyte imbalances.

Nasogastric (NG) Tube Decompression – To relieve pressure from accumulated fluids and gases.

Antibiotics – To prevent or treat secondary infections.

Surgical Treatment

Indicated when:

• Non-surgical reduction fails.
• The patient shows signs of bowel perforation or peritonitis.
• A pathological lead point is suspected.

Surgical intervention may involve manual reduction or resection of necrotic bowel.

Complications of Untreated Intussusception

If left untreated, intussusception can result in severe complications such as:

• Intestinal ischemia
• Necrosis and perforation
• Peritonitis
• Sepsis
• Shock and death

Prognosis

When diagnosed early and managed appropriately, intussusception has an excellent prognosis. Non-surgical reduction by enema is successful in 80–90% of pediatric cases. Recurrence can occur in up to 10% of patients, requiring repeat treatment or surgery.

Intussusception: Key Facts in a Table

Aspect	Details
Definition	Telescoping of one part of the intestine into another
Most Common Site	Ileum into cecum
Age Group	Infants (6–36 months)
Classic Stool	Currant jelly stools (blood + mucus)
Diagnostic Test	Ultrasound (target sign), Barium/Air enema
First-line Treatment	Air or barium enema
Surgical Indications	Failed enema, perforation, peritonitis, pathological lead point
Prognosis	Excellent if treated promptly

Frequently Asked Questions (FAQ)

Q1. What age group is most commonly affected by intussusception?

Infants and toddlers between 6–36 months are most commonly affected.

Q2. What is the hallmark symptom of intussusception?

The passage of currant jelly stools is a classical symptom, although not always present.

Q3. Can intussusception resolve on its own?

Yes, in rare cases, it may spontaneously reduce (passage of normal stools), but medical supervision is necessary.

Q4. How is intussusception diagnosed quickly in emergency settings?

Ultrasound is the best first-line diagnostic tool, showing the characteristic target sign.

Q5. What are the chances of recurrence after treatment?

Recurrence occurs in about 5–10% of cases, often requiring repeat enema reduction or surgery.

Q6. Is intussusception fatal?

If untreated, it can be life-threatening due to ischemia, necrosis, and shock. With timely treatment, prognosis is excellent.