What is the workup for intermittent severe abdominal pain in a 10-month-old infant?

Workup of Intermittent Severe Abdominal Pain in a 10-Month-Old Infant

The workup for intermittent severe abdominal pain in a 10-month-old should begin with abdominal radiography followed by targeted ultrasonography, with particular attention to ruling out intussusception, malrotation with volvulus, and ureteropelvic junction obstruction. 1, 2

Initial Assessment

Key History Elements to Obtain:

• Timing and pattern of pain episodes
• Association with feeding
• Presence of vomiting (especially bilious or forceful)
• Stool patterns (especially bloody stools)
• Recent fever or illness
• Growth and development patterns

Critical Physical Examination Findings:

• Abdominal distension or masses
• Localized tenderness during pain episodes
• "Olive" mass suggestive of pyloric stenosis
• Abnormal bowel sounds
• Signs of dehydration
• Neurological assessment

Diagnostic Algorithm

Step 1: Initial Imaging

• Abdominal radiography should be the first imaging study to evaluate for obstruction patterns, abnormal calcifications, or free air 1

Step 2: Targeted Ultrasonography

• Ultrasound is the preferred second-line imaging for children under 3 years 2
• Specifically evaluate for:
  • Intussusception (target or donut sign)
  • Hypertrophic pyloric stenosis
  • Appendicitis (though less common at this age)
  • Ureteropelvic junction obstruction
  • Mesenteric adenitis

Step 3: Advanced Imaging (if indicated)

• If ultrasonography is inconclusive and symptoms persist:
  • Upper GI series for suspected malrotation
  • CT scan or MRI if obstruction or mass is suspected
  • Consider diuretic scintigraphy if ureteropelvic junction obstruction is suspected 3

Important Diagnostic Considerations

High-Risk Conditions to Rule Out

1. Intussusception - presents with paroxysmal abdominal pain, lethargy between episodes, and possibly bloody stools; more common after 3 months of age 1, 4

2. Malrotation with volvulus - can present at any age with bilious vomiting and severe abdominal pain; surgical emergency 1

3. Ureteropelvic junction obstruction - often overlooked cause of recurrent severe abdominal pain in children 3

4. Appendicitis - though uncommon in infants, should be considered if focal right lower quadrant tenderness is present 2

Common Pitfalls to Avoid

• Dismissing symptoms as colic - by 10 months, typical infantile colic should have resolved
• Attributing symptoms solely to constipation or gastroenteritis without ruling out serious pathology 4
• Delaying diagnosis - children under 3 years with appendicitis have nearly 100% perforation rate due to delayed diagnosis 2
• Inadequate pain management - pain medication does not mask important physical findings and improves examination quality 1

Management During Evaluation

Pain Management

• Provide appropriate analgesia during evaluation
• For infants under 6 months, consider 2 mL of 25% sucrose solution with pacifier before painful procedures 1
• Small titrated doses of opiates can be used without affecting diagnostic accuracy 1

Supportive Care

• Maintain hydration status
• Monitor vital signs closely
• Consider IV access if dehydration present or surgical intervention likely

When to Consult Specialists

• Surgical consultation for suspected intussusception, malrotation, or appendicitis
• Urological consultation for suspected ureteropelvic junction obstruction
• Gastroenterology consultation for persistent symptoms without clear surgical etiology

Remember that young children often cannot localize or describe their pain, making diagnosis challenging. Repeated examinations and observation are valuable tools in assessment 4. Maintain a high index of suspicion for serious pathology, as all significant abdominal emergencies will eventually reveal their true nature.