A systematic approach to the differential diagnosis and management of infant colic

• Working Party – Marks, Archbold, Augstburger, Clayton, Lord, Kanabar, Majid & Morgan •

• Infant colic is defined formally as full-force crying in infants aged 3–13 weeks for >3 hours/day, for >3 days/week; together with spasm and lower limb flexure. In primary healthcare, a more informal definition may simply refer to sustained, excessive crying without obvious cause, together with spasm and limb flexure, in infants aged 1–3 months

• Infant colic affects between 10% and 30% of babies aged 3–13 weeks, whether breast- or formula-fed

• Although not generally considered to be a serious medical condition, colic can lead to failure to thrive. More commonly it contributes to impaired parent-child bonding and may increase the risk of non-accidental injury

• The aetiology of the condition is unclear and thought to be multifactorial. This has led to a proliferation of treatment strategies, none of which are very successful

• The low success rate of current treatments leads to repeat consultations, and in some case the inappropriate use of secondary healthcare facilities

• The diagnosis of infant colic does not describe aetiology and is merely a description of symptoms

Suggested protocol for differential diagnosis and management of infant colic

Level 1

• On presentation determine whether or not there is an apparently organic reason for the baby's symptoms
• If there is, refer to specialist paediatrician or gastroenterologist for further evaluation of aetiology
• If not, implement lactase screen

Level 2

• 24-hour trial with lactase pre-incubation of formula as per pack instructions; in breast-fed infants, pre-incubation of expressed foremilk, which contains much of the lactose in any one feed

• Symptoms abate within 24 hours:
• lactase responders: colic probably due to transient lactase deficiency. Continue with lactase treatment until 3 months and then reduce dose over a week to ensure that treatment has not masked permanent lactose intolerance

• Symptoms unaffected within 24 hours:
• lactase non-responders: switch to low-allergen feed

Level 3

• Low-allergen feed

• Responders:
• maintain on low allergen feed until weaning

• Non-responders:
  • causes might include:
    • non-accidental injuries
    • Munchausen's syndrome by proxy
    • others
  • refer to specialist paediatrician or gastroenterologist for further evaluation of aetiology

• Lactose-free formulae present a valid alternative strategy but have disadvantages:
• breast feeding is withdrawn
• traces of lactose are felt to be important in inducing brush border lactase activity during the physiological and functional maturation of the small intestine
• an approximately 6-fold increase in costs