Intussusception
Definition
Intussusception is the telescoping of a proximal bowel segment into a distal lumen (most commonly ileocaecal). The invaginated bowel drags mesentery with it, causing venous congestion, oedema and, if untreated, ischaemia, necrosis and perforation.
Epidemiology
- Most cases occur in infants and young children (majority between 2 months and 2 years; peak incidence 5-9 months).
- The classic triad - paroxysmal abdominal pain, palpable mass and red‑currant‑jelly stools - appears in only about one third of cases.
- There is a small increased risk after rotavirus vaccination (approx. 2 per 100,000 doses) but the absolute risk is low compared with the benefits of vaccination.
Pathophysiology and risk factors
- In infants most intussusceptions are idiopathic ileocaecal events.
- A pathological lead point (Meckel’s diverticulum, polyp, tumour, postoperative adhesion) is more likely in neonates, older children (>2 years), recurrent episodes or when prior bowel disease or surgery is present.
- Recent bowel surgery or prior intussusception increases recurrence risk.
- Parents should be safety‑netted about post‑vaccination symptoms.
Clinical presentation
Typical pattern
- Intermittent, severe, colicky abdominal pain or distress with the child appearing well between episodes.