At what age is intussusception (intestinal obstruction) most commonly seen?

Age at Presentation for Intussusception

Intussusception is most commonly seen in infants between 3 and 9 months of age, though it can occur at any age. 1

Age Distribution and Epidemiology

• Peak incidence occurs in children 3-9 months of age, making this the most vulnerable period for developing intussusception 1
• Intussusception is unusual in the first 3 months of life, with very few cases reported in neonates 2, 3
• While most common in infants under 1 year, intussusception can present at any age, with decreasing frequency as children get older 2
• Approximately 18.5% of cases occur in children between 5-15 years of age, representing a significant minority of patients 4

Clinical Presentation by Age Group

• In infants (the most common group), the classic triad of symptoms includes abdominal pain, palpable abdominal mass, and bloody stools, though this complete triad is only present in 29-33% of patients 1
• Infants may also present with lethargy or sepsis-like symptoms (45% of cases), making diagnosis challenging 5
• Older children (>3 years) often have more atypical presentations, which can lead to delays in diagnosis 4, 6
• Neonatal intussusception is extremely rare and may mimic necrotizing enterocolitis in premature infants or present as intestinal atresia if it occurs prenatally 3

Etiology and Lead Points by Age

• In infants and young children (<3 years), most cases are idiopathic with no identifiable lead point 6
• In children older than 3 years, pathologic lead points become more common:
  • Meckel's diverticulum is found in approximately 14% of children >3 years old versus only 2% in younger children 6
  • Tumor diagnoses are found in 5-6% of cases across all age groups 6
• In Peutz-Jeghers syndrome (PJS), small bowel polyps can cause intussusception with a cumulative risk of 50-68% during childhood, with 15-30% requiring surgery before age 10 2
• The median age of first intussusception in PJS patients is between 10-16 years 2

Management Considerations by Age

• Enema reduction (barium, air, or saline) is successful in approximately 81% of cases overall 1
• For children >3 years old, enema reduction remains effective in about 62% of cases, despite the higher prevalence of pathologic lead points 6
• In PJS patients, small bowel polyps >1.5-2 cm should be considered for elective resection to prevent intussusception 2
• For neonates, surgical intervention is typically required as enema reduction is rarely successful 3

Special Considerations

• Intussusception has been associated with rotavirus vaccination, particularly with the now-withdrawn RRV-TV (RotaShield) vaccine 2
• The risk was most elevated (>20-fold increase) within 3-14 days after the first dose of RRV-TV 2
• Some evidence suggests that the risk of vaccine-associated intussusception may be age-dependent, with higher risk in infants vaccinated after 60 days of age 2
• In patients with PJS, surveillance for polyps that could lead to intussusception should begin at age 8 years 2

Understanding the age distribution of intussusception is crucial for prompt diagnosis and appropriate management, as delays in diagnosis are associated with significant morbidity 5.