Table 1.

Summary of epidemiology of intussusception

Prevalence
	Highest prevalence in patients aged between 3 and 36 months
	The overall incidence was 28.3/100,000 person-years in children
	Most cases (83%) occurred in patients <3 years old
	Seasonal differences are controversial
Cause
	Idiopathic in most cases
	Recent viral infection
	Recent bacterial gastroenteritis
	Pathologic lead points (Meckel’s diverticulum [m/c], duplication cyst, polyp, lymphoma)
Special consideration
	Preterm: extremely rare, easily confused with necrotizing enterocolitis, usually located in small bowel (91%), infrequent pathologic lead point
	Older age group (>5 years of age): higher incidence of pathologic lead points
	Effect of coronavirus disease 2019 (COVID-19): substantial reduction of incidence of monthly visits (9.0 vs. 3.5) after the active implementation of COVID-19 infection control guidelines initiated in South Korea