✅ Model Answer:
• Diagnosis: Intussusception — intermittent colicky abdominal pain, vomiting, currant jelly stool (blood and mucus), target sign on ultrasound. Most common in children 6-36 months.
• Any other test: Baseline electrolytes, renal function tests, coagulation profile (if surgery needed). Consider stool for occult blood.
• What to do next: Air enema reduction (diagnostic and therapeutic) under fluoroscopic guidance. If fails, peritonitis, or signs of perforation → surgical reduction.
• Follow-up plan: Observe for recurrence (24-48 hours), advance diet after successful reduction, monitor for bowel perforation, stool passage.

✅ Model Answer:
• Classic triad:
- Intermittent colicky abdominal pain — child draws knees to chest, cries, then becomes quiet between episodes
- Vomiting — initially bilious (if obstruction distal to ampulla of Vater)
- Currant jelly stool — stool mixed with blood and mucus (late sign, indicates ischemia)
• Other features:
- Pallor and lethargy
- Abdominal distension
- Sausage-shaped mass in the right upper quadrant (RUQ)
- Empty right lower quadrant (Dance's sign)

✅ Model Answer:
• Most common type: Ileocolic intussusception (terminal ileum invaginates into the ascending colon).
• Most common site: Ileocecal junction (around 90% of cases).
• Other types: Ileocecal, colocolic, jejunojejunal (less common).
• Pathologic lead point: Found in 2-5% of cases — Meckel's diverticulum, polyp, lymphoma, duplication cyst, Henoch-Schönlein purpura.
• Peak age: 6-36 months (most common in 5-10 months).

✅ Model Answer:
• Ultrasound — preferred initial imaging modality:
- Target sign (doughnut sign) on transverse view — hyperechoic center (intussusceptum) with hypoechoic rim (intussuscipiens)
- Pseudokidney sign on longitudinal view
- High sensitivity (98-100%) and specificity
- No radiation
• Abdominal X-ray:
- May show sparse gas, soft tissue mass (sausage-shaped)
- Paucity of gas in the right lower quadrant
- Signs of obstruction (air-fluid levels)
- Limitations: Normal in 50% of cases
• Contrast enema (air or barium): Diagnostic and therapeutic

✅ Model Answer:
• Non-surgical management (image-guided reduction):
- Air enema (pneumatic reduction) — preferred method, success rate 80-90%
- Barium enema (hydrostatic reduction) — used less commonly now
- Procedure: Under fluoroscopic or ultrasound guidance, insufflate air or instill contrast to reduce the intussusception
- Success criteria: Free flow of air/contrast into the small bowel
- Contraindications: Perforation, peritonitis, shock, >48 hours of symptoms
- Recurrence rate: 10-15% after successful reduction

✅ Model Answer:
• Surgical indications:
- Failed enema reduction (after 2-3 attempts)
- Perforation (free air on X-ray)
- Peritonitis or signs of bowel ischemia/necrosis
- Shock or hemodynamic instability
- Symptoms >48 hours (higher risk of ischemia)
- Pathologic lead point (Meckel's diverticulum, polyp, lymphoma)
- Recurrent intussusception
• Surgical procedure: Laparotomy or laparoscopic reduction, resection if bowel necrosis present.

✅ Model Answer:
• Complications:
- Bowel ischemia and necrosis (due to compromised blood supply)
- Perforation (during enema reduction or due to necrosis)
- Peritonitis
- Septic shock
- Recurrence (10-15% after successful reduction)
- Bowel obstruction (adhesions or stricture)
- Short bowel syndrome (if extensive resection)
- Death (rare if treated promptly)
- Lead point (pathologic) — Meckel's diverticulum, polyp, lymphoma

✅ Model Answer:
• Recurrence rate:
- 10-15% after successful non-surgical reduction
- Higher in: Children <6 months, those with pathologic lead point, or after failed reduction
- Recurrence usually occurs within 48 hours to 6 months
• Follow-up:
- Observe for 24-48 hours after successful reduction
- Advance diet gradually once bowel function returns
- Monitor for recurrence — parents should be educated about symptoms
- Repeat enema if recurrence occurs
- Surgical evaluation if recurrent or suspected lead point
- Prognosis: Excellent with prompt diagnosis and treatment. Mortality <1%.