Infantile Colic

Prepared and reviewed by the PrepElephant Academic Review Team

First published 15 Oct 2026 · Spot an error?

Reference basis: Nelson Textbook of Pediatrics; Ghai Essential Pediatrics

On this page

Direct answer
What you must remember
A bedside pathway for the crying baby
Where the exam tries to catch you
Frequently asked questions
Related topics

Direct answer

Infantile colic is paroxysmal, inconsolable crying in an otherwise healthy, well-fed infant, defined by the rule of threes. It usually begins around 2 to 3 weeks of age and settles by 3 to 4 months. Colic is a diagnosis of exclusion, so infection, feeding problems and surgical causes must be ruled out before the label is applied.

What you must remember

Rule of threes: crying for more than 3 hours a day, on more than 3 days a week, for more than 3 weeks.
Onset and resolution: typically begins around 2 to 3 weeks of age and resolves by 3 to 4 months.
Pattern: crying clusters in the evening, with drawing up of the legs, a red face and clenched fists.
Red flags: fever, vomiting, poor weight gain, blood in the stool or lethargy all point away from colic.
Differential diagnosis: gastro-oesophageal reflux, cow's milk protein allergy, urinary tract infection, intussusception, incarcerated hernia and hair tourniquet.
Hair tourniquet: a strand of hair wound around a digit, toe or the penis, causing constriction that is easily missed.
Avoid: honey under 1 year because of botulism risk, and anticholinergic drugs such as dicyclomine, which are not recommended in infants.
Probiotic evidence: Lactobacillus reuteri has some supporting evidence in breastfed infants, though the benefit is modest.

A bedside pathway for the crying baby

A 3-week-old is brought in at 9 pm, crying for two hours with legs drawn up, and the parents are exhausted. The examination must come before the label, since the same crying can hide a treatable cause.

Exclude red flags: check temperature, weight, hydration and the abdomen, and look carefully at the fingers, toes and genitals for a hair tourniquet.
Review feeding: check technique, volume and posseting, and consider a trial of a cow's milk protein exclusion only if the features suggest allergy.
Reassure the parents: explain the natural course, which usually resolves by 3 to 4 months and does no lasting harm.
Offer soothing measures: holding, swaddling, rhythmic motion, white noise and a pacifier are all reasonable first steps.
Consider a probiotic: Lactobacillus reuteri may be offered to breastfed infants, with the benefit explained as modest.
Review and refer: if crying remains unexplained or any red flag appears, arrange a review or investigation.

Where the exam tries to catch you

Colic is easy to diagnose wrongly because crying is the only symptom parents report.

Trap: labelling every crying infant as colic. Correct: colic is a diagnosis of exclusion, and fever, poor weight gain or vomiting need investigation.
Trap: using simethicone or dicyclomine as routine treatment. Correct: simethicone has not shown consistent benefit, and dicyclomine is not recommended in infants because of its anticholinergic effects.
Trap: missing a hair tourniquet in a crying baby. Correct: examining the digits and genitals is essential, since constriction can cause ischaemia if it goes unnoticed.

Frequently asked questions

What is the rule of threes in infantile colic?

The rule of threes defines infantile colic as crying for more than three hours a day, on more than three days a week, for more than three weeks. It applies to healthy, well-fed infants. The definition helps separate colic from more serious causes of crying.

Which conditions should be excluded before diagnosing infantile colic?

Infection, feeding problems and surgical causes must be excluded before diagnosing infantile colic. Urinary tract infection, intussusception, incarcerated hernia, hair tourniquet and cow's milk protein allergy are common mimics. Fever, vomiting and poor weight gain are red flags.

Is simethicone effective for infantile colic?

Simethicone has not shown consistent benefit for infantile colic in trials, so it is not recommended as routine treatment. Parents often try it, and it is generally harmless. Soothing measures and reassurance remain the mainstays of management.

When does infantile colic usually resolve?

Infantile colic usually resolves by 3 to 4 months of age, although it can last longer in some babies. Its onset is typically around 2 to 3 weeks. Parents need reassurance about this natural course.