Air or contrast enema reduction
Colon to the point of obstruction and beyond following reduction
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Reduction of ileocolic intussusception confirmed on ultrasound.
- Contrast enema for suspected distal bowel obstruction in a neonate.
Technique
- Performed with surgical cover available, since perforation and irreducibility both require immediate surgery.
Where it goes wrong
- Peritonism, perforation or shock contraindicate attempted reduction — the child needs a surgeon, not a radiologist.
Clinical questions that reach this study
Contrast
Acquisition
Phases
Each phase is authored once and shared across every protocol that uses it, so the physiology below is the same wherever you meet it.
- Rectal contrastInstilled through a rectal catheter immediately before the acquisition, under gravity, to patient tolerance. Confirm locally.
Retrograde filling opacifies the distal lumen directly, without waiting for transit. The transferable principle is that a distal question is best answered from the distal end: an antegrade oral agent arrives late, diluted and unreliably, whereas retrograde instillation guarantees opacification and, just as importantly, guarantees a pressure head across the segment of interest. That pressure is the diagnostic mechanism — extraluminal contrast becomes positive evidence of a leak or fistula rather than an inference from adjacent gas or fluid. Water-soluble agents are used rather than barium precisely because a leak is what is being looked for, and spilled barium causes chemical peritonitis.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- Child-sized technique and contrast dose· radiographer at scan
- Pregnancy status before an ionising exposure· radiographer at scan