Intussusception case study
The case
Patient: A 10‑month‑old male infant, previously healthy, fully immunised, exclusively breast‑fed until 6 months and now on mixed solids.
Presenting complaint: Sudden onset of intermittent, severe abdominal pain for the past 6 hours. The parents describe the child “crying inconsolably for a few minutes, then appearing normal for a short period” and this pattern has repeated 4–5 times.
History of present illness:
- Onset: 6 hours ago, while the child was playing on the floor.
- Pain: Colicky, lasting 2–3 minutes per episode, with a “drawing up of the legs” posture.
- Vomiting: One episode of non‑bilious, projectile vomiting 2 hours after pain began; no further emesis.
- Stool: No passage of stool since the onset of pain. The parents note a small amount of bright red, jelly‑like stool (“currant‑jelly stool”) on the diaper after the second episode of pain.
- Feeding: Appetite reduced; the child refused the last bottle.
Past medical history: Unremarkable. No previous surgeries, no known allergies.
Family history: No gastrointestinal disorders; no known hereditary diseases.
Social history: Lives with parents in an urban apartment; no exposure to sick contacts.
Examination (at 09:30 h):
| Parameter | Value |
|---|---|
| General | Irritable, intermittently crying, appears pale |
| Vital signs | Temp 37.8 °C, HR 138 bpm, RR 32 /min, BP 78/44 mmHg, SpO₂ 98 % on room air |
| Weight | 9.2 kg (≈50th percentile) |
| Abdomen | Distended, visible peristalsis, palpable “sausage‑shaped” mass in the right upper quadrant, tenderness on deep palpation, no guarding or rigidity |
| Rectal exam | Small amount of red, gelatinous stool on glove |
| Other systems | Normal |
Initial investigations:
| Test | Result |
|---|---|
| CBC | Hb 11.2 g/dL, WBC 13.5 × 10⁹/L (neutrophils 68 %), platelets 320 × 10⁹/L |
| CRP | 6 mg/L (reference <5) |
| Electrolytes | Na 138 mmol/L, K 4.2 mmol/L, Cl 102 mmol/L, HCO₃⁻ 22 mmol/L |
| Blood gas (venous) | pH 7.34, pCO₂ 42 mmHg, HCO₃⁻ 22 mmol/L |
| Abdominal ultrasound (bedside) | “Target” or “donut” sign in the right upper quadrant, measuring 2.5 cm in transverse diameter; mesenteric vessels seen converging toward the centre; no free fluid. |
| Plain abdominal X‑ray (AP) | Nonspecific gas pattern, mild distension of small bowel loops, no air‑fluid levels. |
The child is kept nil per os (NPO), IV access obtained, and a bolus of 20 mL/kg isotonic saline is administered.
Questions
- What is the most likely diagnosis?
- Which clinical and radiological findings support this diagnosis, and why are they pathognomonic?
- Outline the step‑wise investigation algorithm for a suspected intussusception in a child under 2 years, including the role of contrast studies.
- Describe the current (2023‑2024) management plan, from initial resuscitation to definitive therapy, and indicate when surgical intervention is required.
- Discuss the possible complications of intussusception and the measures to prevent or monitor them.
Answers
1. What is the most likely diagnosis?
Intussusception – the telescoping of a proximal segment of bowel (intussusceptum) into a distal segment (intussuscipiens). In infants, the classic presentation is colicky abdominal pain, vomiting, and “currant‑jelly” stool. The bedside ultrasound showing a target sign clinches the diagnosis.
2. Which clinical and radiological findings support this diagnosis, and why are they pathognomonic?
| Finding | Reason it points to intussusception |
|---|---|
| Intermittent colicky pain with leg‑drawing | Pain arises from intermittent obstruction as the bowel telescopes and reduces spontaneously. |
| Projectile, non‑bilious vomiting | Obstruction is proximal to the ampulla of Vater; bile has not yet entered the vomitus. |
| Currant‑jelly stool | Mucosal sloughing and venous congestion lead to blood‑stained mucus. Although not always present, it is highly suggestive. |
| Palpable “sausage‑shaped” mass (right upper quadrant) | Represents the telescoped bowel segment; palpable in ~50 % of cases. |
| Target (donut) sign on ultrasound | Concentric rings of hypoechoic bowel wall surrounding an echogenic mesenteric fat core; sensitivity ≈ 98 % and specificity ≈ 95 % (AAP 2023). |
| Absence of free air on X‑ray | Rules out perforation; supports a non‑perforated obstructive process. |
| Mild leukocytosis | Reflects inflammatory response; not specific but common. |
The combination of classic clinical triad (pain, vomiting, red mucus) plus the ultrasound target sign makes the diagnosis virtually certain.
3. Outline the step‑wise investigation algorithm for a suspected intussusception in a child under 2 years, including the role of contrast studies.
- Initial assessment – ABCs, vitals, fluid status, NPO.
- Bedside abdominal ultrasound – First‑line imaging; look for target sign, pseudokidney sign, and assess for free fluid.
- If ultrasound is inconclusive – Perform a contrast‑enhanced (water‑soluble) enema (either fluoroscopic or ultrasound‑guided). The contrast will both diagnose (show a “coiled‑spring” appearance) and often reduce the intussusception.
- If enema fails to reduce or clinical deterioration (peritonitis, perforation, shock) – Proceed to surgical exploration (laparotomy or laparoscopy).
- Adjunct labs – CBC, electrolytes, coagulation profile; not diagnostic but guide resuscitation.
Key points from guidelines:
- The American Academy of Pediatrics (AAP) Clinical Report 2023 recommends ultrasound as the initial modality in stable patients.
- NICE guideline NG147 (2022) advises that a therapeutic contrast enema should be performed promptly after confirming the diagnosis, provided there are no signs of perforation.
4. Describe the current (2023‑2024) management plan, from initial resuscitation to definitive therapy, and indicate when surgical intervention is required.
| Phase | Action | Rationale |
|---|---|---|
| Resuscitation | • NPO, IV access, isotonic fluid bolus 20 mL/kg (repeat if needed) <br>• Correct electrolyte disturbances <br>• Analgesia (IV paracetamol 15 mg/kg) <br>• Antiemetics (ondansetron 0.15 mg/kg) | Prevent hypovolaemia, maintain perfusion, improve comfort before reduction. |
| Diagnostic confirmation | Bedside ultrasound (already done). | High sensitivity; avoids radiation. |
| Non‑operative reduction | Air‑contrast enema under fluoroscopic guidance (preferred) or hydrostatic (saline) enema under ultrasound guidance. <br>• Sedation with IV ketamine (1 mg/kg) or inhalational nitrous oxide as per institutional protocol. <br>• Reduction attempted up to 3 times, each lasting ≤ 3 minutes, with a maximum pressure of 120 mm Hg (air) or 100 mm Hg (hydrostatic). | Success rates 80‑90 % for air enema; lower perforation risk than barium. |
| Post‑reduction care | • Observe for 4–6 hours (vital signs, abdominal exam). <br>• Repeat ultrasound to confirm complete reduction. <br>• Resume feeds gradually (breast milk or formula) if stable. | Detect early recurrence (≈ 10 % within 24 h). |
| Indications for surgery | • Peritonitis, perforation, or hemodynamic instability. <br>• Failure of non‑operative reduction after 3 attempts or > 24 h of symptoms. <br>• Pathologic lead point suspected (e.g., Meckel’s diverticulum, polyp, lymphoma). | Surgical reduction (laparoscopic or open) allows manual reduction and resection of lead point if present. |
| Surgical technique | • Laparoscopic reduction preferred when expertise available; otherwise, open reduction via a small transverse supra‑umbilical incision. <br>• If bowel viability is compromised, perform limited resection with primary anastomosis. | Minimises postoperative pain and adhesions; resection prevents recurrence when lead point present. |
Follow‑up: Outpatient review at 1 week and again at 1 month; educate parents on signs of recurrence.
5. Discuss the possible complications of intussusception and the measures to prevent or monitor them.
| Complication | Pathophysiology | Clinical features | Prevention / Monitoring |
|---|---|---|---|
| Bowel ischemia / necrosis | Prolonged venous congestion → arterial compromise. | Persistent pain, abdominal rigidity, metabolic acidosis, rising lactate. | Early reduction; monitor vitals, serial abdominal exams, repeat labs (lactate, ABG). |
| Perforation | Necrotic bowel wall ruptures; also iatrogenic during enema (high pressure). | Free air on X‑ray, sudden abdominal distension, sepsis. | Use recommended pressure limits; stop enema if patient becomes unstable; surgical backup ready. |
| Recurrence | Incomplete reduction or persistent lead point. | Return of pain/vomiting within 24‑48 h. | Observe for ≥ 6 h post‑reduction; educate caregivers; consider repeat ultrasound if symptoms recur. |
| Sepsis | Bacterial translocation from compromised gut. | Fever, tachycardia, leukocytosis, hypotension. | Prompt antibiotics if perforation suspected; aseptic technique during enema. |
| Short‑bowel syndrome (rare) | Extensive resection of necrotic bowel. | Malabsorption, failure to thrive. | Preserve viable bowel; limit resection to non‑viable segments only. |
| Anesthesia‑related complications | Sedation for enema or surgery. | Respiratory depression, allergic reaction. | Use age‑appropriate dosing; monitor oxygenation and heart rate continuously. |
Early recognition and timely intervention are essential to minimise morbidity and mortality, which remain < 1 % in centres with experienced pediatric teams.
Key learning points
- Intussusception is the most common cause of intestinal obstruction in infants 6 months–2 years; classic triad is abdominal pain, vomiting, and currant‑jelly stool.
- Ultrasound is the first‑line diagnostic tool; the target (donut) sign has > 95 % specificity.
- Air‑contrast enema is both diagnostic and therapeutic; success rates 80‑90 % with a low perforation risk when pressure limits are respected.
- Immediate fluid resuscitation and correction of electrolyte abnormalities are mandatory before attempting reduction.
- Surgical reduction is indicated for perforation, peritonitis, failed enema reduction, or a suspected pathological lead point.
- Recurrence occurs in ~10 % of cases; observation for at least 4–6 hours post‑reduction and parental education are crucial.
- Complications include bowel necrosis, perforation, sepsis, and short‑bowel syndrome; early detection hinges on vigilant clinical monitoring and repeat imaging when needed.
- Follow‑up includes a repeat ultrasound (if indicated), assessment of feeding tolerance, and counseling on warning signs.
Practice MCQs
1. A 9‑month‑old infant presents with intermittent abdominal pain, vomiting, and a palpable “sausage‑shaped” mass. Ultrasound shows a target sign. Which of the following is the most appropriate next step?
A. Immediate laparoscopic reduction
B. Barium enema under fluoroscopy
C. Air‑contrast enema under fluoroscopic guidance
D. Observation for 12 hours and repeat ultrasound
Answer: C — Air‑contrast enema is the preferred first‑line therapeutic reduction in a stable patient with confirmed intussusception; it has a high success rate and lower perforation risk than barium.
2. Which of the following findings would be an absolute contraindication to attempting a non‑operative enema reduction?
A. Mild leukocytosis (WBC 13 × 10⁹/L)
B. Presence of free intraperitoneal air on plain X‑ray
C. Currant‑jelly stool
D. Age > 12 months
Answer: B — Free intraperitoneal air indicates perforation; attempting an enema could worsen the perforation and is therefore contraindicated.
3. After successful air‑contrast reduction of an intussusception, the child is observed for 6 hours. Which of the following is the most appropriate discharge criterion?
A. Normal abdominal exam and tolerating oral feeds without vomiting
B. Absence of fever for 24 hours
C. Repeat ultrasound showing a residual 1 cm thickened bowel loop
D. Complete resolution of the palpable mass but persistent mild abdominal distension
Answer: A — The child can be discharged once the abdominal exam is normal, the child tolerates oral feeds, and there are no signs of recurrence; the other options indicate possible residual pathology or incomplete recovery.
Get a new patient case, answer the examiner's questions by voice or text, and get marked — free.
Try a case on MEDOSTMore in Paediatrics
The patient is invented for teaching. AI-assisted study material for exam revision. Always confirm with standard textbooks and current guidelines; not medical advice.