Suspected intussusception in a child

ACR AC Abdominal Pain–Child; ACR AC Suspected Intussusception; Image Gently

Two studies, two jobs. Ultrasound makes the diagnosis and is close to definitive in experienced hands; the air or contrast enema that follows is the definitive treatment, not a confirmatory investigation. Vetting this request therefore means booking a procedure — a child who is resuscitated, a paediatric surgeon who knows, and a room that can decompress a tension pneumoperitoneum on the spot. CT has no place in the initial assessment.

Typically a child between about three months and three years with intermittent inconsolable crying, drawing up the legs, vomiting, lethargy between episodes, and sometimes blood in the stool.

Referenced decision support — confirm against your local protocol.

Decision support, not a directive. Protocols and timings shown are typical published ones — your local protocol takes precedence, and the vetting radiologist decides.

The request in front of you

Everything is optional. Leave a field alone and the answer assumes nothing — the verdict updates as you go.

Study requested

What the referrer actually asked for. It is evidence of intent, not a constraint on the right answer.

Contrast as written

What the request form says, not what it should say.

Age

Pick a band, or type an exact age if it matters.

years

Pregnancy status

Haemodynamic state

The fact that lets a pathway waive its own requirements. A crashing patient does not wait for a score.

Renal risk factors

The question a vetter can actually answer from the request. An explicit “none known” is a real answer, and it removes checks rather than deferring them.

Previous contrast reaction

The pathway — tap anything already done

Marking a study complete moves the answer on. A patient arrives partway through a pathway far more often than at the start of one.

Accept as requested

Paediatric abdominal ultrasound

What we'd amend, and why

Ultrasound shows the invaginated bowel directly — the target or doughnut appearance in cross-section and the pseudo-kidney appearance longitudinally — with very high sensitivity and specificity, in a small abdomen that is ideally suited to high-frequency probes. It carries no ionising radiation and requires no sedation, and it also identifies the features that predict a failed reduction, such as trapped fluid and absent flow in the intussusceptum.

Nothing needs resolving before this goes ahead. Routine checks below are owned downstream.

How was this decided?

pathwaychild — Children

Decision support only. Local protocol takes precedence.

Worth asking the referrer (2)

None of these hold the request up. They sharpen the protocol or the plan that follows.

Is there peritonism, shock or suspected perforation?
These are contraindications to attempted enema reduction and redirect the child straight to surgical assessment and resuscitation.
Is paediatric surgical cover available on site now, and can the room decompress a tension pneumoperitoneum immediately?
These are the preconditions for attempting reduction at all. Where either is absent the correct plan is ultrasound and transfer, and knowing that at vetting saves an hour that matters.

Pathways

Big forks are separate pathways; the first whose conditions match is the one used.

Shocked or peritonitic child — surgical emergency, not a reduction candidate

Role	Study & protocol	Why this answers the question
First line	Paediatric abdominal ultrasound Paediatric abdominal ultrasound usually appropriate	The diagnostic ultrasound still stands, and it is the right study for an unwell child: it is performed at the cot side in minutes, needs no radiation, no contrast and no sedation, and it shows the invaginated bowel directly along with the free fluid and the absent flow in the intussusceptum that predict a failed reduction. It is done alongside resuscitation and an immediate call to the paediatric surgeons, not as a step that has to complete before they are told. Nothing on this arm sends an unstable infant to CT — the dose is substantial, the answer is no better, and the child is not stable enough for the journey.
Second line	Abdominal radiograph Abdominal radiograph — supine	The one radiograph that earns its place in an unstable child answers a specific surgical question — free intraperitoneal gas and the degree of obstruction — rather than screening for the intussusception itself, which it cannot exclude.
Second line	Contrast or air enema Air or contrast enema reduction usually not appropriate	Reduction is withdrawn here rather than merely deferred. Shock, peritonism and established perforation are contraindications to insufflating the colon, and this card says so in its own enema rationale: that child needs a surgeon, not a radiologist. Attempting it converts a resuscitation into a perforation risk in a child with no physiological reserve, and the reduction can be revisited only if the surgical team resuscitates the child and judges it appropriate. Where the diagnosis is made but reduction cannot proceed — here, or in a unit without paediatric surgical cover and immediate decompression of a tension pneumoperitoneum in the room — the correct plan is the ultrasound diagnosis and transfer.

This arm is a statement about the enema only. The ultrasound is still urgent and still the first thing radiology does.
If resuscitation restores stability and the surgical team is present and content, the child rejoins the standard pathway and reduction is attempted under the usual conditions.

Children

Matches your inputsDefault

Role	Study & protocol	Why this answers the question
First line	Paediatric abdominal ultrasound Paediatric abdominal ultrasound usually appropriate	Ultrasound shows the invaginated bowel directly — the target or doughnut appearance in cross-section and the pseudo-kidney appearance longitudinally — with very high sensitivity and specificity, in a small abdomen that is ideally suited to high-frequency probes. It carries no ionising radiation and requires no sedation, and it also identifies the features that predict a failed reduction, such as trapped fluid and absent flow in the intussusceptum.
Second line	Contrast or air enema Air or contrast enema reduction usually appropriate	This is the treatment. Air or contrast enema reduces the great majority of ileocolic intussusceptions non-operatively, and in doing so it converts a laparotomy into an afternoon in the fluoroscopy room — so it sits after the ultrasound only because the diagnosis has to be made before the colon is insufflated, not because it is a lower-ranked test. Reduction is confirmed by free reflux of air or contrast into the terminal ileum with resolution of the mass, which is why the study is both the diagnosis and its own outcome measure. It must be requested as a procedure: the child resuscitated and consented, a paediatric surgeon informed and available before insufflation begins, and immediate decompression of a tension pneumoperitoneum possible in the room. Perforation is rare, of the order of well under one percent of attempts, but it is instantaneous and its management is measured in seconds. Peritonism, shock or established perforation are contraindications — that child needs a surgeon, not a radiologist — and a unit that cannot meet these conditions should make the diagnosis on ultrasound and transfer.
Second line	Abdominal radiograph Abdominal radiograph — supine	An abdominal radiograph is useful only for the specific questions of obstruction and free intraperitoneal gas before an attempted reduction. It cannot exclude intussusception, and using it as a screening test delays the ultrasound that would have made the diagnosis.

The order here is a sequence within one episode of care, not a ladder of increasingly good tests: ultrasound diagnoses, and the enema — pneumatic or hydrostatic, fluoroscopically or ultrasound-guided depending on local practice — treats, immediately afterwards in the stable child.
A request that names the enema directly is not wrong about the destination, only about the first move: the intussusception is confirmed sonographically on arrival before any air is instilled, including where an outside hospital has already scanned.
Recurrence after successful reduction is not rare, so a child who re-presents needs the same pathway again rather than a different one.

Pitfalls

Accepting a CT request. In this presentation CT delivers dose to a small child and answers a question ultrasound has already answered better.
Reading a normal abdominal radiograph as excluding intussusception.
Reporting an incidental short small-bowel–small-bowel intussusception in a way that triggers an unnecessary reduction attempt.
Scanning without looking specifically in the right upper quadrant and along the line of the colon, where the ileocolic intussusceptum is usually found.
Sending a child for reduction without the surgical team knowing, or without the contraindications having been checked.
Treating the enema as an investigation to be booked on a list. It is the definitive treatment and it belongs in the same episode as the diagnostic ultrasound, in a room that can decompress a tension pneumoperitoneum.
Attempting reduction in a hospital with no paediatric surgical cover because the diagnosis has already been made and the case feels straightforward.

Priors — what to pull first

A previous episode raises the likelihood of a pathological lead point, particularly outside the typical age range, and that changes what the report should look for.
Recent viral illness or a recent rotavirus vaccination is useful context for the referring team.

What makes a good request

Diagnosis and treatment are one visit: confirmatory ultrasound is normally followed immediately by air or fluid enema reduction, so the request should be vetted as the start of a therapeutic episode rather than as an isolated scan.
The enema is not a radiology-only decision. It is attempted where paediatric surgical cover is immediately available and where the room and staff can decompress a tension pneumoperitoneum without leaving it — needle or angiocatheter decompression must be to hand before insufflation starts. A unit without both should diagnose on ultrasound and transfer rather than attempt reduction locally.
Lethargy without pain is a recognised and easily missed presentation.
Small-bowel to small-bowel intussusception found incidentally is usually short, transient and does not need reduction; the ileocolic intussusception, usually in the right upper quadrant, is the one that does.

How these studies are acquired

Contrast, phases and timing for every study on the pathways above.

Paediatric abdominal ultrasound Abdominal radiograph — supine Air or contrast enema reduction

Confirm locally

Timings, contrast volumes and rates above are typical published values. Your department's protocol, scanner and patient population decide the actual numbers.
Safety thresholds and premedication policy follow local policy where it differs from the cited guidance.

References

Implemented from the cited published sources. Educational and workflow support only; confirm against current guidelines and local policy before clinical use.