Most Common Cause of Abdominal Pain in Childhood
In otherwise healthy children, functional (non-organic) abdominal pain is the most common cause of chronic abdominal pain, while acute appendicitis is the most common surgical emergency requiring immediate attention in children aged 10-30 years. 1, 2, 3
Age-Specific Considerations
The etiology of abdominal pain varies significantly by age group, requiring different diagnostic approaches:
Infants and Preschoolers (Under 5 Years)
- Constipation is a leading cause of abdominal pain in young children and can localize to the right lower quadrant, often mimicking more serious conditions 1, 4, 5
- Gastroenteritis, reflux, and constipation account for most non-surgical conditions in this age group 6
- Intussusception is more common in children under 5 years and typically presents with intermittent colicky pain, vomiting, and potentially bloody stools 1
School-Age Children and Adolescents (5-18 Years)
- Functional abdominal pain disorders represent the most common cause overall, accounting for approximately 34% of chronic abdominal pain cases 5, 2, 3
- Functional constipation is present in 10% of children presenting with chronic abdominal pain, though it is frequently overlooked as a primary cause 5
- Acute appendicitis is the most common cause of acute abdominal pain requiring surgery in children aged 10-30 years, with the classic triad of right lower quadrant pain with rebound tenderness, nausea, and vomiting 1
Critical Diagnostic Framework
When to Suspect Organic Disease
Alarm symptoms that increase the likelihood of organic pathology include: 2, 3
- Weight loss
- Gastrointestinal bleeding
- Persistent fever
- Chronic severe diarrhea
- Significant vomiting
Common Overlooked Diagnoses
Functional constipation deserves special attention because 47.5% of children with constipation experience some form of abdominal pain, yet only 12% present with pain as their sole complaint, leading to frequent underdiagnosis 5. This is particularly important because delayed recognition may lead to poor prognosis.
Most Frequent Causes in Clinical Practice
Based on a large pediatric cohort study, the distribution of diagnoses in children presenting with abdominal pain to hospital was: 7
- 44.7% had inflammatory diseases of the alimentary tract (predominantly gastritis at 25.7%, with 12.4% having H. pylori infection)
- 32.3% had functional disorders (dyspepsia in 22.1%)
- 11.5% had parasitic diseases (ascariasis in 8.8%)
- 11.5% had other disorders
Practical Clinical Approach
Initial Assessment Strategy
For most children presenting to primary care with chronic abdominal pain, diagnostic testing is rarely indicated 2, 3. The majority of children experience spontaneous resolution without specific management, and for every 15 school-age children with abdominal pain, at most 1 will have a serious condition such as appendicitis 6.
Key Pitfalls to Avoid
- Do not dismiss constipation as a cause of significant abdominal pain, even when it is not the presenting complaint 5
- Do not assume psychological factors distinguish functional from organic pain, as anxiety and depression are common in both groups and cannot discriminate between them 2, 3
- Do not delay evaluation in young children (under 5 years) with atypical presentations, as they have higher rates of delayed diagnosis and complications 1
- In infants, bilious vomiting heralds a life-threatening or surgically indicated disorder and requires immediate evaluation 6
When Imaging Is Indicated
For acute presentations where appendicitis is suspected:
- Ultrasound of the right lower quadrant should be the first-line imaging modality (sensitivity 82-99%, specificity 94-96%) 1, 4
- If ultrasound is equivocal and clinical suspicion persists, proceed directly to CT with IV contrast or MRI (sensitivity 90-94%, specificity 94-98%) rather than repeating ultrasound 1