Criteria for diagnosis of infant colic

Based on: Pettitt C, “Criteria for diagnosis of infant colic in the AECC clinic,” AECC Project List, 1999.

Infant colic remains one of the most challenging and emotionally taxing conditions encountered in early pediatric care. Persistent crying in an otherwise healthy infant can create distress for families and uncertainty for clinicians. In 1999, C. Pettitt outlined clinical criteria used at the AECC Clinic to guide the diagnosis of infant colic, helping bring structure and clarity to what is often considered a diagnosis of exclusion (Pettitt, 1999).

This post summarizes the diagnostic framework described in that project and explores its practical implications in clinical settings.

Understanding Infant Colic

Infant colic is typically defined as episodes of excessive, inconsolable crying in an otherwise healthy and well-fed infant. Classic descriptions often reference the “rule of threes”:

• Crying for more than 3 hours per day

• Occurring on more than 3 days per week

• Persisting for at least 3 weeks

However, Pettitt (1999) emphasized that diagnosis in the AECC clinical setting relied not only on duration and frequency but also on structured clinical observation and exclusion of other causes.

Core Diagnostic Criteria (AECC Clinical Framework)

According to Pettitt (1999), the diagnosis of infant colic within the AECC clinic was based on the following elements:

1. Excessive Crying Pattern

• Prolonged, intense crying episodes

• Typically occurring in the late afternoon or evening

• Crying that appears disproportionate to identifiable triggers

2. Age Range

• Onset generally within the first few weeks of life

• Most common between 2–12 weeks

• Symptoms tend to resolve spontaneously by 3–4 months

3. Physical Presentation During Episodes

Infants may display:

• Facial flushing

• Drawing legs up toward the abdomen

• Abdominal tension or distension

• Clenched fists

• Arching of the back

These behaviors suggest visceral discomfort but occur in the absence of diagnosable pathology.

4. Normal Growth and Development

A key diagnostic feature is that the infant:

• Feeds adequately

• Gains weight appropriately

• Demonstrates normal developmental milestones

This helps differentiate colic from underlying gastrointestinal, metabolic, or neurological disorders.

5. Exclusion of Other Causes

Pettitt (1999) emphasized the importance of ruling out:

• Infection

• Gastroesophageal reflux

• Milk protein intolerance

• Hernias

• Otitis media

• Other identifiable medical conditions

Infant colic was considered a diagnosis of exclusion following appropriate clinical evaluation.

Clinical Context at AECC

The AECC clinic (Anglo-European College of Chiropractic, now known as AECC University College) operated within a chiropractic teaching environment. Within that setting, assessment included:

• Detailed perinatal history

• Birth history (including delivery type and complications)

• Feeding history

• Musculoskeletal examination

• Cranial and spinal assessment

The framework aimed to identify infants presenting with colic-like symptoms while ensuring safe referral when red flags were present.

Red Flags Requiring Referral

The criteria underscored the importance of recognizing symptoms inconsistent with simple colic, such as:

• Fever

• Persistent vomiting

• Bilious emesis

• Blood in stool

• Failure to thrive

• Lethargy

Presence of these findings necessitated immediate medical referral.

Why Structured Criteria Matter

Without clear criteria, “colic” can become a catch-all label for unexplained crying. Pettitt’s framework provided clinicians with:

• A systematic method of assessment

• Clear exclusion parameters

• Documentation standards

• Improved communication with parents

For families, receiving a structured explanation of why their infant meets criteria for colic — and reassurance that serious conditions have been ruled out — can significantly reduce anxiety.

Practical Takeaways for Clinicians

1. Use defined crying duration and frequency thresholds.

2. Confirm normal growth and feeding.

3. Conduct thorough history and physical examination.

4. Screen carefully for red flags.

5. Treat colic as a diagnosis of exclusion.

Even though diagnostic frameworks have evolved since 1999, the foundational principle remains: careful clinical evaluation is essential before labeling an infant with colic.

Conclusion

Infant colic is a functional diagnosis grounded in pattern recognition and exclusion of pathology. Pettitt’s 1999 AECC clinical criteria offered a structured, safety-focused approach to diagnosing infant colic within a chiropractic teaching clinic.

While research and clinical guidelines continue to evolve, the importance of systematic assessment, parental reassurance, and appropriate referral remains central to high-quality pediatric care.

Citation

Pettitt C. Criteria for diagnosis of infant colic in the AECC clinic. AECC Project List. 1999.

Pettitt C, "Criteria for diagnosis of infant colic in the AECC clinic", AECC Project List 1999