Colic

Colic is commonly described as a behavioral syndrome characterized by excessive, paroxysmal crying. Colic is most likely to occur in the evenings, and it occurs without any identifiable cause. During episodes of colic, an otherwise healthy neonate or infant aged 2 weeks to 4 months is difficult to console. They stiffen, draw up their legs, and pass flatus. Colic is one of the common reasons parents seek the advice of a pediatrician or family practitioner during their child's first 3 months of life.

The most widely used definition of colic was used by Wessel et al.[8] Their definition is based on the amount of crying (ie, paroxysms of crying lasting >3 h, occurring >3 d in any week for 3 wk).

Colic is a poorly understood phenomenon. It is equally likely to occur in both breastfed and formula-fed infants. Although potential adverse sequelae have been described, the disorder is generally believed to be self-limited and benign. Different feeding practices and crying may result in large amounts of air entering the gastric lumen, which suggests that excessive aerophagia may be associated with colic. Colonic fermentation is the second proposed source of excessive intestinal gas in infants. However, no experimental evidence supports either theory.

Increased levels of certain biochemical markers, such as motilin, alpha lactalbumin, and urinary 5-hydroxy-3-indole acetic acid (5-OH HIAA) have been associated in infants with colic. Data from one study suggested that psychosocial stress during pregnancy is associated with babies who develop colic.[9] Further research is needed to establish a causal relationship of these factors to colic.

Although anticholinergic drugs have proven effective, they are not recommended because of their serious adverse effects. Parental anxiety can be minimized if the physician discusses colic, offers insight on future expectations, and answers the parents' questions. Reassure the parents about the generally benign and self-limiting nature of the illness. A caring and compassionate healthcare provider remains the cornerstone in the management of colic, a problem for which effective therapy remains elusive.[10]

The term colic derives from the Greek word kolikos or kolon, suggesting that some disturbance is occurring in the GI tract. Researchers have also postulated nervous system, behavioral, and psychologic etiologies. 

A meta-analysis indicated that colic may be a form of migraine headache rather than, as has been proposed, a GI condition. The analysis utilized 3 studies (891 subjects total), one of which indicated that there is a greater likelihood of colic in infants whose mothers have migraine headaches and the other two of which indicated that infants with colic are more likely to experience migraine in childhood and adolescence. Using a pooled random effects model in their analysis, Gelfand and colleagues found the odds ratio for an association between migraine and colic to be 5.6.[11, 12]

In a secondary analysis, which included two additional studies (both of which also looked at the colic/migraine link but addressed a different primary research question), the odds ratio for the association between migraine and colic was 3.2.[11]

International

Colic affects 10-30% of infants worldwide.

Increased susceptibility to recurrent abdominal pain, allergic disorders and certain psychological disorders may be seen in some babies with colic in their childhood.

Sex

This condition is encountered in male and female infants with equal frequency.

Age

The colic syndrome is commonly observed in neonates and infants aged 2 weeks to 4 months.

Colic remains a diagnosis of exclusion. Crying by infants with or without colic is mostly observed during evening hours and peaks at the age of 6 weeks. The cause of this diurnal rhythm is not known. The amount of crying is not related to an infant's sex; the mother's parity; or the parents' socioeconomic status, education, or ages.

On acoustic analysis, colicky crying differs from regular crying. Compared with regular crying, colicky crying is more variable in pitch, more turbulent or dysphonic, and has a higher pitch. Mothers of infants with colic, unlike mothers of infants without colic, rate the cries as more urgent, discomforting, arousing, aversive, and irritating than usual.

Obtain a detailed history about the timing, the amount of crying, and the family's daily routine. The benign nature of colic should be emphasized. Rule out causes of excessive crying in an infant, such as having hair in the eye, strangulated hernia, otitis, and sepsis.

Perform physical examination to confirm normalcy. Infants with colic often have accelerated growth. Weight gain is typical, whereas failure to thrive should make one suspicious about the diagnosis of colic.

GI causes may include but are not limited to gastroesophageal reflux, overfeeding, underfeeding, milk protein allergy, and early introduction of solids. Parental anxiety and parental stress has been a subject of many studies. Postpartum depression may lead to stress in parents, which may be transferred to the infant, resulting in excess crying.

Other causes include inexperienced parents or incomplete or no burping after feeding. Incorrect positioning after feeding may contribute to excessive crying. Note that colic is not limited to the first-born child, casting doubt on the theory about inexperienced parenting as the etiologic factor.

Some epidemiologic evidence suggests that exposure to cigarette smoke and its metabolites may be related to colic. Maternal smoking and exposure to nicotine replacement therapy (NRT) during pregnancy may be associated with colic.[1] In one study, prenatal nicotine exposure was associated with an elevated risk for infantile colic in offspring. This was true both in women who smoked during pregnancy and those who used nicotine replacement therapy compared with unexposed women. Partners’ smoking was not associated with infantile colic after adjustment for maternal smoking.[2]

Some evidence has linked persistent crying in young infants to food allergy.[3] An association between colic and cow's milk allergy (CMA) has been postulated.[4] Data from one study suggested an association between low birth weight and increased incidence of colic.[5]

Some reports have focused on intestinal microflora and its association with colic.[6] Lower counts of intestinal lactobacilli were observed in infants with colic compared with infants without colic.[7]

The results of a Dutch study that followed the temporal development of intestinal microbiota from birth to approximately 100 days in 24 infants suggested that early differences in the development and composition of gut flora may be at the root of infant colic.[13, 14] At 2 weeks, babies later diagnosed with colic had significantly less microbial diversity and stability than their healthy counterparts, as well as more than twice the abundance of proteobacteria and significantly reduced levels of Bacteroidetes. These differences were all seen in the first month of life, before the colic peak, and usually disappeared by 3 to 4 months of age, when colic usually resolves.

Laboratory studies are usually not indicated in colic unless the physician suspects another condition, such as gastroesophageal reflux.

If the patient's stools are excessively watery, testing them for excess reducing substances (Clinitest) may be worthwhile. If results are positive, this may be an indication of an underlying GI problem, such as acquired (postinfectious) lactose intolerance. Stool may be tested for occult blood to rule out cow's milk allergy (CMA).

Irritability and crying may be associated with gastroesophageal reflux disease because of the pain associated with esophagitis.

Rule out common causes of crying is the first step in treating an infant with persistent crying (ie, colic). Recommend that the parents not exhaust themselves and encourage them to consider leaving their baby with other caretakers for short respites.

Drug treatment generally has no place in the management of colic, unless the history and investigations reveal gastroesophageal reflux.

Consistent follow-up and a sympathetic physician are the cornerstones of management.

Many benign but unproven treatment modalities are available for colic.

Although GI factors do not seem to cause colic in most patients, clinicians continue to treat infants with colic based on this hypothesis.

Dicyclomine hydrochloride is an anticholinergic drug that has been proven in clinical trials to be effective in the treatment of colic. However, because of serious, although rare, adverse effects (eg, apnea, breathing difficulty, seizures, syncope), its use cannot be recommended.

Wessel and colleagues suggested an association between family and infantile tension. Some families with infants with colic may have more problems in their family structure, family functioning, and affective state, compared with families with infants without colic.

A maternal low-allergens diets (ie, low in dairy, soy, egg, peanut, wheat, shellfish) may offer relief from excessive crying in some infants.

Lactobacillus reuteri endogenous to the human GI tract was found to relieve colic symptoms in breastfed infants within one week of treatment. This was compared with simethicone or placebo, which suggests that probiotics may have a role in treatment of infantile colic.[6, 15]

In a more recent study, 167 infants with colic who were fed formula or breast milk were randomly assigned to receive either L reuteri DSM 17938 (108 colony-forming units) or placebo daily for 28 days.[16]  No benefit was noted in babies who were exclusively fed breast milk or formula; however, a gradual improvement in colic was noted in both groups. No change was noted in fecal microbial diversity, Escherichia coli colonization or calprotectin levels in the intervention group. The largest prevention trial enrolled 589 infants, starting in their first week of life; they received L reuteri DSM 17938 or placebo for 90 days.[17]  A 50% reduction in crying time and regurgitation and more frequent bowel movements were noted in the L reuteri group compared with the placebo group. No differences in weight gain were noted, and no adverse events were related to the supplementation. The study concluded that L reuteri DSM 17938 at a dose of 108 colony-forming units per day reduced the onset of functional GI disorder, reduced private and public cost of care, and was well tolerated and safe.

Results on the effectiveness of probiotics for the prevention and treatment of colic are thus far inconclusive, based on a 3 systematic reviews.[18, 19, 20] . Eight prevention and nine randomized, controlled trials using probiotics have been performed. Of these, 6 used Lactobacillus rhamnosus GG, 9 used L reuteri, and 2 used Bifidobacterium Lactis as a probiotic. Of those using L reuteri, 1 prevention and 6 treatment trials showed consistent benefit in breast-fed babies. A meta-analysis of these studies found that infants treated with L reuteri had a reduced risk of crying time at 14 days and 21 days compared with placebo in breast-fed babies but not in formula-fed babies; the difference was less apparent at 4 weeks, and this was based on 6 studies that involved 423 infants.[20]  Further studies are needed before this can be recommended as a routine therapy for colic in infants due to a lack of clarity involving its mechanism of action and its effect on long-term health.[21]

Oral hypertonic glucose and sterile water were compared for treatment of colic in infants in a randomized trial. In the group receiving glucose, 30% had significantly less colic than the placebo group.[22]

Evidence for the efficacy of spinal manipulation in treating infantile colic is inconclusive. Physicians should be cautious about recommending spinal manipulations in infants.[23, 24]

Some psychodynamic factors may possibly play a role from the prenatal to the postnatal period. Some studies demonstrated that behavioral management was effective in reducing excessive crying. Dealing with family problems and extending help to mothers is an integral part of this management.

An excellent review of various studies with nutritional supplements and other complementary medicines has recently been published.[25] Many of these studies have design flaws, biases, and poor descriptions of adverse effects. It is a common misconception that natural means safe. This review concludes that there may be encouraging results for fennel extract, mixed herbal tea, and sugar solutions.

More randomized control studies and rigorous methodologies need to be applied to the studies before any recommendations can be made about the use of natural supplements and nutritionals.

Commercial products, including car-ride simulators, infant swings, lambskin or sheepskin blankets, and womb-sound recordings, have not been proven effective, may not be without adverse effects, and can be expensive.

Remind parents about the importance of feeding a hungry baby, changing wet diapers, and comforting a baby who is cold and crying as a result of these factors. Soothing music accompanied with parental attention (including eye contact, talking, touching, rocking, walking, and playing) may be effective in some infants and is never harmful.

Encourage parents to discuss their feelings and concerns with each other to obtain support. Emphasize the responsibility of the whole family in the care of a baby with colic.

Dietary changes may include the following:

• Eliminate cow's milk protein only in cases of suspected intolerance to the protein (eg, positive family history, eczema, onset after the first month of life, association with other GI symptoms such as vomiting or diarrhea).

• The symptoms of allergy to cow's milk protein generally start later than those of colic (mean age, 13 wk), though early onset is also well known.

• In infants with suspected allergy to cow's milk protein, a protein hydrolysate formula, such as Pregestimil or Nutramigen (Mead Johnson) or Alimentum (Ross Pharmaceuticals) is indicated.

• Uncommonly, amino acid–based formulas such as Neocate (Nestle) or Elecare (Ross Pharmaceuticals) may be needed to manage suspected cow's milk allergy (CMA), although evidence may be lacking for management of infants with colic. Cost and availability of such formulas also tend to be prohibitive for routine use in infants with excessive crying.

• Use of soy-based formula is not recommended because many infants allergic to cow's milk protein may also develop intolerance to soy protein.

Simethicone is a nonabsorbable medication that changes the surface tension of gas bubbles, allowing them to coalesce and disperse and releasing the gas for easier expulsion. Experimental evidence does not support its use in colic.

Sedatives, such as phenobarbital, chloral hydrate, and alcohol (gripe water) should never be used, however tempting. Herbal remedies have been used in many cultures. The common ingredients include chamomilla, bitter apple, and fenugreek. Only a handful of studies of herbal products have been conducted, and additional studies of their safety and efficacy are needed.

Consistent follow-up and a sympathetic physician are the cornerstones of management in patients with colic.

Parental anxiety can be minimized if the physician discusses colic, offers insight on future expectations, and answers parental questions.

Reassure the parents about generally the benign and self-limiting nature of the illness.