Could a patient with resolved abdominal pain, persistent tenderness on the right side of the umbilical region, brief loss of consciousness, and vomiting be diagnosed with intussusception?

Could This Be Intussusception?

Intussusception is unlikely in this clinical scenario, but cannot be definitively excluded without imaging given the persistent right periumbilical tenderness and vomiting. The resolved abdominal pain and brief loss of consciousness suggest alternative diagnoses should be prioritized, particularly syncope with a gastrointestinal trigger or other acute abdominal pathology.

Why Intussusception is Less Likely

• Intussusception classically presents with intermittent, crampy abdominal pain that waxes and wanes, not pain that completely resolves 1. The hallmark is episodic severe pain as the bowel telescopes and reduces spontaneously 2, 3.

• In adults, intussusception most commonly presents with abdominal pain (72%), nausea (49%), and vomiting (36%) 4. However, the pain is typically persistent or recurrent, not fully resolved 4.

• The classic pediatric triad of abdominal pain, hematochezia, and palpable abdominal mass is rarely seen 5. This patient lacks bloody stools and a palpable mass.

• Intussusception is unusual in the first 3 months of life in infants, and in adults typically has an identifiable lead point (60% of cases), such as a mass or tumor 1, 4. Without prior abdominal surgery or known pathology, this becomes less probable.

Critical Red Flags That Require Immediate Evaluation

• Brief loss of consciousness (syncope) is NOT a typical feature of intussusception and suggests:

  • Vasovagal response to severe pain or vomiting
  • Hypovolemia from fluid losses
  • Cardiac arrhythmia
  • Other neurologic or cardiovascular pathology

• Persistent right periumbilical tenderness despite resolved pain warrants imaging to exclude:

  • Early appendicitis (can present with periumbilical pain migrating to right lower quadrant) 6
  • Small bowel obstruction from adhesions 1, 7
  • Mesenteric ischemia
  • Other intra-abdominal pathology

Recommended Diagnostic Approach

Immediate assessment should include:

• CT abdomen and pelvis with IV contrast is the diagnostic test of choice, with sensitivity of 85.7-100% and specificity of 94.8-100% for detecting intussusception and alternative diagnoses 6, 8. CT can identify the characteristic "target sign" or "bowel-within-bowel" appearance of intussusception 9.

• Ultrasound can be considered as first-line imaging (particularly in younger patients or to avoid radiation), using graded compression technique 8. However, CT provides superior diagnostic accuracy for adult abdominal pathology 8.

• Laboratory evaluation should include complete blood count, electrolytes, renal function, and lactate to assess for leukocytosis, dehydration, and bowel ischemia 1.

Management Algorithm

1. Stabilize the patient first:

   • IV fluid resuscitation with crystalloids 7
   • Anti-emetics for nausea/vomiting 1
   • Evaluate syncope episode (orthostatic vital signs, ECG if indicated)

2. Obtain imaging while symptoms are present or shortly after:

   • The diagnostic yield is significantly higher when imaging is obtained during symptomatic episodes 2. In one case report, CT obtained after pain resolved showed only the mass lesion, but repeat CT during pain demonstrated active intussusception 2.

3. If intussusception is confirmed on imaging:

   • Adults typically require surgical intervention, especially with identifiable lead points 4, 9
   • Reduction before resection is controversial in adults, with a shift toward primary resection without reduction, particularly for colonic intussusception 9
   • Approximately 20% of adult intussusceptions are asymptomatic and discovered incidentally 4, but symptomatic cases presenting to emergency departments are more likely to require surgery 4

4. If imaging is negative but symptoms recur:

   • Consider diagnostic laparoscopy, which can identify transient intussusception that reduces spontaneously 3
   • Serial abdominal examinations every 6-12 hours 6

Common Pitfalls to Avoid

• Do not dismiss persistent tenderness even if pain has resolved – this may represent evolving pathology or transient intussusception 2, 3.

• Do not delay imaging in adults with suspected intussusception – unlike pediatric cases where contrast enema is both diagnostic and therapeutic, adults typically have underlying pathology requiring surgical resection 4, 9.

• Do not attribute syncope solely to intussusception – investigate cardiovascular and neurologic causes concurrently.

• Consider that approximately 60% of adult intussusceptions have an identifiable lead point (tumor, polyp, Meckel's diverticulum) 4, so if intussusception is confirmed, malignancy workup is essential 2, 9.