Colic

Introduction

Colic, derived from a Greek term kolikos, meaning colon, was first defined by Wessel as crying for at least three hours per day, for at least three days per week, for a period of three weeks or longer in an otherwise healthy infant1. It has been further refined in Rome IV classification of functional gastrointestinal disorders reducing three week period to a 7-day duration criteria and defined as “An infant who is less than five months of age when symptoms start and stop; recurrent and prolonged periods of infant crying, fussing or irritability reported by caregivers that occur without any obvious cause and cannot be prevented or resolved by caregivers; no evidence of infant failure to thrive, fever or illness.” It is common in the first few months of life (up to 5 months) with reported incidence of 4% to 28% worldwide².

Discussion

British anthropologist stated “sound of a crying baby…is just about the most disturbing, demanding, shattering noise we can hear”. Colic has been described as a factor in child abuse and infanticide³. The etiology of colic is unknown, but is likely to be multifactorial including gastrointestinal, hormonal, neurodevelopmental, psychosocial factors, and inflammation or dysbiosis.

Gastrointestinal factors include gas production, lactose intolerance, intolerance to substances in maternal diet like cruciferous vegetables (cauliflower, cabbage, broccoli), chocolate; cow’s milk protein allergy and poor feeding techniques such as underfeeding or overfeeding, infrequent burping. There have been reports but no convincing literature available that excessive gas production causes colic although it may be a contributing factor. Similarly, conflicting results have been obtained from clinical trials of oral lactase administration for infants making association between lactose intolerance and colic unclear. Systematic reviews and trials have shown that using protein hydrolysate formulas in infants with Cow’s milk protein allergy, whether breast or formula fed, can decrease crying times in these infants⁴.

Psychosocial factors like parental anxiety, maternal and paternal depression, inadequate parental interaction, maternal smoking, and advanced maternal age have been described as contributors to or causes of colic with different studies showing different results with no proven causality^5-6.

Higher levels of serotonin have been shown to be associated with colic in infants. Mothers with migraine have been reported to have infants twice as likely to have colic. Colic has also been described as reduced ability to regulate crying episodes in infants.

Alteration in gut flora or dysbiosis has been extensively studied as a contributor or a cause of colic. Study by Wessel et al.1 describing colic in 1954 had implicated abnormal faecal composition as a potential cause of colic. Infants with colic have been found to have increased faecal calprotectin, a marker of gut inflammation⁷. The theory of dysbiosis-inflammation suggests that aberration colonization of gut creates an environment which could affect brain function and behaviour in an infant or newborn. Studies have shown significant decrease in anti-inflammatory commensals (Bifidobacterium, Lactobacillus, Bacteroides) in infants with colic⁸.

Clinical features include infants being described to have a colicky cry which is different from usual cry, is more piercing, urgent and seemingly in pain. This can be associated with facial flushing, increased tone in limbs, flatulence and withdrawing of legs towards abdomen. Colic can begin by 2-3 weeks of age, peaking around 6 weeks and can last up to 5 months. Barr Baby day dairy, Ames Cry score, Infant colic scale, ROME IV functional questionnaire have been developed as a means of analysis of crying in infants.

Colic is a diagnosis of exclusion in a well thriving infant with organic causes to be ruled out. There are no established guidelines for treatment of colic. However, proper counselling of parents forms the cornerstone of management. Commonly used techniques include swaddling while prone, environmental stimulation (white noise, soft sounds), giving gripe water have been beneficial but not scientifically studied. Acupuncture⁹ and chiropractic therapies¹⁰ have been studied in clinical trials with inconclusive evidence so far needing further research and randomised controlled trials. Herbs such as fennel, herbal tea, chamomile and medications such as simethicone, cimetropium, dicyclomine, sucrose, acid-blockers have been trialled for use in colic with several over the counter preparations available in the market. They are unproven safety and efficacy and are not recommended as first line for treatment.

Lactobacillus reuteri, a normal faecal commensal, has been investigated as probiotic drops with a dose of 5 drops containing more than 20 million colony-forming units and a meta-analyses found that there was a weighted mean difference of 28-56 minutes in crying time with best effect at 2-3 weeks of use¹¹. A Cochrane analyses¹² studying prophylactic use of probiotics (Lactobacillus reuteri DSM, Lactobacillus rhamnosus, Lactobacillus paracasei and Bifidobacterium animalis) concluded that there was no difference in occurrence of new cases of infantile colic despite 40% less cases of infantile colic in probiotic group. There were no serious adverse effects seen with use of probiotics and a meta-analsyses found that the crying time was reduced with use of probiotics. However, due to limitations of sparse data, heterogeneity in study population, risk of bias, the use of probiotics has not been advised in practice.

Infants with colic have an excellent prognosis regardless of etiology. The vast majority of these stop crying by 4-5 months of age. However, a 10-year follow up study of 52 children with severe colic vs other infants showed that children who had experienced colic as an infant were more likely to develop recurrent abdominal pain, allergic diseases, fussiness, aggressiveness, sleeping. It can also be a significant stressor for parents which leads to self-doubt, premature termination of breast feeding or in the worst case scenario, child abuse¹³.

In conclusion, colic is multifactorial in origin with clinical diagnosis and wide variety of treatment options available and mostly resolving by 4-5 months of life.