Infant colic is challenging for new parents and is a reason for 10% to 20% of pediatrician visits during the early weeks of an infant's life. Colic is estimated at affecting 5% to 40% of infants worldwide. The condition typically presents in the second or third week of life, peaks around 6 weeks, and resolves by the age of 12 weeks in 60% of infants and by 16 weeks of age in 90%. Inconsolable crying, irritability, and screaming without an obvious cause characterize colic; during these episodes of fussiness, which occur more frequently in the evenings, the affected infant classically appears red-faced, draws up the legs and tenses up the abdomen. The traditional methods of soothing the infant often fail to relieve the infant's distress. First described in 1954, the original "Wessel's Rule of 3s" diagnostic criteria (symptoms lasting for 3 hours per day, 3 or more days per week, for 3 or more weeks, starting around 3 weeks of age), has undergone a transition in recent years. The Rome IV criteria describe colic in infants from birth to 5 months of age to make the definition of infantile colic more consistent for research purposes. The criteria are as follows:
- An infant who is <5 months of age when the symptoms start and stop
- Recurrent and prolonged periods of infant crying, fussing, or irritability reported by caregivers that occur without obvious cause and cannot be precented or resolved by caregivers
- No evidence of infant failure to thrive, fever, or illness
While benign and self-limiting, the condition is frustrating for parents and has been linked to maternal postpartum depression and shaken baby syndrome. Since treatments for colic are controversial and inconsistent, the role of the physician as a counselor and educator to parents is critical.
Despite its prevalence, a clear cause for infantile colic remains elusive. There have been many theories regarding the etiology, but a lack of uniformity in study definitions for colic have made it challenging to identify a common cause. It is likely that the etiology of the condition is multifactorial. Many of the theories regarding the cause focus on immaturity of the nervous system, sleeping disruption, hypersensivitiy to the environment, sensory overload, food allergy, reflux, and a lower diversity of the gut microbiota. In breastfeeding infants with colic, maternal diets containing cow's milk may contribute to infant distress. Others have suggested a link between colic and migraine physiology, as there are a growing number of studies showing an association between infantile colic and the later development of childhood migraines. Psychosocial issues have also been blamed, such as poor feeding techniques, maternal smoking, or nicotine replacement therapy, inadequate parental interaction, family tension, and parental anxiety. Unfortunately, this wide range of potential causes makes the treatment for colic challenging for both parents and physicians.
Colic affects around 20% of infants worldwide, although some studies suggest the prevalence may be significantly higher. A recent population-based survey in the United States suggested a prevalence rate of nearly 6%. These ranges in prevalence may reflect the previous lack of uniformity in defining colic. However, the recognition of colic also depends on the parental perception of crying intensity and duration. Parental wellbeing, as well as cultural differences in what is considered acceptable crying, may also affect these data. Regardless of the variability in prevalence, there is no association with gender, ethnicity, socioeconomic status, feeding preference or birth order.
Because a precise etiology for colic is unclear, the theories of pathophysiology are equally varied. An underlying organic disease is found in less than 5% of infants with inconsolable crying. Most pathways still focus on a GI process. The latest research has focused on the gut microbiota. Having a lower diversity in bacteria may be associated with a diagnosis of colic.
History and Physical
Although colic is a benign and self-limiting condition, a thorough history, physical examination, and reviewing growth charts are important to rule out more serious issues. After obtaining information regarding the pattern, frequency, circumstances, duration, and intensity of crying, the health care provider should take care to obtain information regarding fever, growth, feeding patterns, the presence of bilious emesis, constipation or diarrhea, bloody stools, lethargy, cough, wheezing, rash. The physical exam should then focus on identifying signs of failure to thrive or serious illness. Findings such as poor weight gain or growth, abdominal distension and tenderness, scrotal or inguinal swelling, suspicious bruises or burns, and signs of dehydration should prompt further evaluation. Findings such as a hair wrapped around a digit or penis should not be missed.
In the absence of significant physical findings and a history that is consistent with the Rome IV criteria or the "Rule of 3s" the diagnosis of colic can be made confidently, and further evaluation is unnecessary. However, the presence of fever may necessitate a workup for sepsis and involve blood and urine cultures, imaging and even lumbar puncture. Abdominal distension may suggest the need for abdominal radiography or ultrasonography, while positive fecal occult blood testing may support suspected cow's milk allergy. Increased lethargy should prompt consideration for a septic workup and computed tomography (CT) of the brain. Suspicion for traumatic injury should be evaluated by skeletal surveys and CT of the head. If the crying starts after the third month of life or persists beyond the fourth month of life then further work up is indicated.
- Emergent management of Otitis media
- Bacterial meningitis imaging
- Pediatric aseptic meningitis
- Pediatric oesophageal reflux
Infantile colic is a benign and self-limiting condition that typically resolves spontaneously between three and four months of age. However, there are some indications that infants with colic may be at more risk for developing migraines without aura by age 18. There is also evidence linking excessive crying early in life with preschool adaptive problems, attention deficit hyperactivity disorder, and other behavioral problems, as well as being associated with maternal anxiety and depression. Thus, counseling parents regarding colic and helping them to develop coping mechanisms, as well as offering suggestions on the management of colic symptoms, seems prudent.
Pearls and Other Issues
In the absence of other obvious causes, infants who meet the Rome IV criteria can be confidently diagnosed with colic. These criteria, which are modifications of the original "Rule of 3s" include inconsolable crying or fussiness for 3 or more hours per day, during 3 or more days for 1 or more weeks. Etiologies are likely multifactorial, and treatment recommendations vary based on those potential etiologies. However, the strongest evidence for effective treatment recommendations includes eliminating potential allergens (cow's milk being the most common) from the diets of mothers who are breastfeeding and switching bottle-fed infants to hydrolyzed formulas. Weaker levels of evidence also support supplementing breastfed infants with Lactobacillus reuteri but do not endorse supplementing formula-fed infants with those probiotics.
Enhancing Healthcare Team Outcomes
Infantile colic is managed by a number of healthcare professionals including the family practitioner, pediatrician, pediatric gastroenterologist, emergency department physician, nurse practitioner, and obstetrician. Infantile colic is a distressing challenge for parents and is a reason for 10% to 20% of pediatrician visits during the early weeks of an infant's life. Colic is estimated at affecting 20% of infants worldwide. The condition typically presents in the second or third week of life, peaks around 6 weeks, and usually resolves between 12-16 weeks. Inconsolable crying, irritability, and screaming without an obvious cause characterize colic. Today, the Rome IV criteria are often used to make the definition of infantile colic more consistent for research purposes. The criteria are as follows:
- Episodes of fussing or crying that start and stop without obvious causes
- Episodes lasting 3 or more hours daily, 3 or more days a week for 1 or more weeks
- Episodes without evidence for failure to thrive
While benign and self-limiting, the condition is frustrating for parents and has been linked to maternal postpartum depression and shaken baby syndrome. Since treatments for colic are controversial and inconsistent, the role of the clinician as a counselor and educator to parents is critical.
The pediatrician, pediatric gastroenterologist, nurse practitioner, and primary care provider should minimize parental anxiety by discussing colic and ensuring that it is a benign disorder. Infants should be brought back frequently to assess growth as well as screen the caregiver for depression. Parents should also be educated to put the infant back in the crib by the interprofessional team so as to avoid shaking or hurting the infant with unproven remedies. Finally, the pharmacist should warn parents against the use of dicyclomine and other related agents as the risks outweigh any potential benefit.
The outcome for most infants with colic is excellent.