Infant colic/Citable Version

Infant colic is persistent inconsolable crying in otherwise healthy infants between the ages of two and sixteen weeks. It is a syndrome – a defined set of symptoms and signs – not a disease. The only more or less standard definition is crying that lasts for more than three hours, on more than three days per weeks, for more than three weeks. When infant colic occurs in full-term babies, it starts by two weeks of age and subsides by age four months. The onset in premature infants is delayed by the duration of prematurity, that is, if the baby was born three weeks prematurely, infant colic starts five (three plus two) weeks after birth, and may last until near five months of age.

An average English speaker would interpret the term colic to refer to a cramp like pain arising from a hollow viscus, but since such an etiology for the excessive crying is not known, the term is likely to be a misnomer. Indeed, as far as scientific medicine is concerned, infant colic is a syndrome which has no known cause, no known harmful effects (other than that on the parents, which may unfortunately be reflected onto the baby, with potentially disastrous consequences), and no specific treatment. Self-limited, it begins and ends by itself. Given such vagueness, and the absence of any cause or known ill effect, there is some dispute that infant colic even exists as a true medical disorder. In other words, although there is a phenomonom of infants who have a particularly distressed sounding cry that is excessive in occurance, and these infants show the onset at cessation of the crying at around the same (gestational) age, the actual underlying causes of the crying may bear no relation from baby to baby, instead, it may be that- at that time of life, crying something that some babies do easily and often in response to a great number of totally different normal stimuli. If that is the case, the "cause" of infant colic may never be determined, but the fact that the syndrome itself is not a sign of danger or disease can be used to reassure parents.

The reader should not infer that this condition is entirely innocent or inconsequential. While the crying, as such, is no direct threat to the baby’s health, it can certainly undermine the infant's health indirectly. Persistent distress that is triggered in parents and other children may have serious consequences for the baby's immediate physical well-being, intra-family relationships, and future attitudes towards the child. Infant colic has been identified as a significant risk for the Shaken Baby syndrome, and up to 70% of mothers of colicky babies entertain explicitly aggressive thoughts towards the child, while 26% have fantasies of infanticide. This cannot be taken lightly.

This article sets out to describe what is meant by the complaint, what is known about possible causes, what treatments may be used, and what the short- and long-term consequences of the condition may be.

A closer look at the symptoms

Crying increases from birth to about 6 weeks, and then decreases to a more or less steady time per day for more than a year. A baby may be on any of these curves, but if he is on the top one there is a good chance that his parents will complain of colicky crying, while in the pink shaded area.

Normally a baby starts crying at birth, with awake time being divided between feeding, lying still, learning to use its muscles and senses, "fussing", and crying. The amount of crying time per day increases up to a maximum at about six weeks of age, and then decreases significantly to become more or less stable at sixteen weeks. (See graph)

Infant colic is not a recent problem. Hiscock and Jordan quote a description from the sixteenth century "The boke of chyldren", of problems crying related to "noyse and romblying in the guttes". A working definition, the "Wessel criteria", formulated as long ago as 1954, defines infant colic as crying lasting more than three hours a day, on more than three days a week, for more than three weeks, in an otherwise well baby. Originally crying and "fussiness" were described together, as symptoms which appear and disappear without reason or long-term meaning, but more recent workers consider that the two are not the same; crying is transient both in its manifestations and implications, while fussiness seems to be a more stable personality trait.

The cardinal symptom of infant colic is persistent inconsolable crying. This usually starts after two weeks of age. The crying occurs in bouts or paroxysms, most frequently in the evening (almost half occurs between six o'clock in the evening and midnight). During the attack the babies face is contorted in apparent pain (though the eyes may remain open, and the child appear alert, in contrast to, for instance, needle stick and post-operative pain). The legs are drawn up and the whole body is rigid – neck, back, abdomen, and limbs. The attacks are frequently associated with the passing of flatus.. Not everyone agrees that the clinical signs that are here described are necessary for the diagnosis.

The incidence of infant colic is uncertain, with quoted figures varying from 5% to 25% of infants at six weeks after birth. Definitions may differ in subtle ways, changing the incidence significantly. As an example, using Wessels criteria, but rephrasing the “more than three” (>3) to “at least three” (≥3), admits fourfold the number of babies to the diagnosis. Furthermore, studies may take into account the effect on parents, classifying infant colic by the parents’ perception of consolability, their opinions about the child being colicky, or of them being distressed by the crying. Thus, when applying ten different published definitions of infant colic, an incidence varying from 2% to 18% for the same group of babies was found. Figures of between 15% and 20% are commonly quoted.

The cry of a colicky baby is no different from that of a non-colicky infant. It tends to be high-pitched, which caregivers associate with increased levels of distress in the infant (this is so for all babies, not only colicky infants), but what the cause or implication of the cry is cannot be inferred from the that. The interpretation of the cry depends on the listener, not on the crier. It may be that the strong statistical correlations between, on the one hand, the factors of maternal psychological difficulties in pregnancy, family discord, maternal age and socio-economic status, and, on the other hand, the complaint of a colicky baby, are related by the mother’s interpretation of a cry that cannot be interpreted, rather than by any effect of these factors on the infant. The same may be true for the father, which has important implications for the prevention of infant abuse.

Postulated causes and associated conditions

There are a number of popular hypotheses for what causes infant colic, which can be broadly classed as gut-theory or developmental-psychosocial theory. It is frequently claimed that "the real problem" is one or more of the conditions of gastro-esophageal reflux, food allergy, lactose intolerance, bowel spasm or gas, and maternal and family psychosocial disturbances. Others claim that "there is no real problem", that the baby is normal and the excessive crying represents the upper range of normal development up to 12 weeks age. The absence of elevated cortisol in babies with severe colic would indicate that there is indeed no pain, only crying, which would favour the normal development theory.

Normal crying starts at birth, and increases to an average of about 140 minutes per day by six weeks of age – this “age” being taken as if the baby had been born at full term, and frequently referred to as "gestational age", meaning the time lapsed since the baby was conceived. Thus, for an infant born two weeks prematurely, this "six weeks" is in reality eight weeks after the birth. Crying in babies has a definite diurnal rhythm, tending to occur more frequently in the evening. The posturing associated with crying spells, such as the facial changes, pulling up of legs and passing of wind that was described above for colic, is reported by many mothers who have no complaints about their child being colicky, or an excessive crier. The body signs are therefore unlikely to be specific to colic. Normally, crying decreases significantly by sixteen weeks of age. If it does not abate, but persists beyond six months of age, then an assessment for an underlying undiagnosed disease should undertaken. This bears repetition: the pattern of an increase in crying from birth to six weeks, and then a rapid decrease to a steady level by sixteen to twenty, is a normal pattern and occurs in all human societies that have been studied. It is not a reflection of poor or indifferent baby care; it is an expression of the normal development of the baby. It definitely does not mean that the parents are abusing or mistreating the baby. Much of what is called "colic" may be a normal event, interpreted by the parents in a negative way – a reflection of their own psycho-dynamics. Stated another way, the baby does not have a complaint, he is simply crying; the parent has the complaint.

While the diagnosis of infant colic implies that there is no known underlying organic disease causing the crying, the diagnosis can quite easily be wrong. Statistically, 5% or less of babies may have an actual illness or correctable disturbance causing the crying. The rest of this section is applicable to this small proportion of colicky infants.

Acute illnesses (for instance infections or injuries) frequently have crying as a major symptom, which is one of the reasons why prolonged inconsolable crying should be assessed by a health worker, rather than having the caregivers manage the episodes of excessive crying as colic, until more symptoms appear. It is highly recommended that caregivers seek a professional opinion early on in the course of excessive crying - this is the wise course of action, not hypochondiasis by proxy. Persistent diarrhoea, rashes, vomiting and failure to gain weight argue even more strongly for a proper assessment of the baby. It is equally wise to remember that when the health worker has not identified a definite cause for the crying, this does not exclude more serious problems with anything like 100% certainty, and conversely, where a separate disease has been diagnosed, its treatment will not necessarily solve co-incidental colic.

Lack of sleep and hunger are treatable causes of crying. The former may be due to excessive stimulation of the baby while awake, and this may be a factor in the finding that a reduction in stimulation seems to improve the complaints. Insufficient feeding requires advice and practical help to the mother about ways of increasing and monitoring the baby’s milk intake.

Food allergies may be a cause for excessive crying in both bottle-fed and breastfed babies. Mother's milk, cow’s milk and soy milk could be responsible, since they all contain allergens - in the case of breast milk, these may derive from the mother's diet. Changing the mother’s diet, or changing the bottle formula may be beneficial, but specific testing is usually not justified. In some cases a hypoallergenic formula yields benefits. This cannot be predicted before the change, and the reason for the benefit is usually not known. A confounding factor is that colic resolves by itself, so that a benefit from the change in diet may coincide with a normal resolution of the excessive crying, leading to a false impression of efficacy. To illustrate this error, consider a baby who is experiencing a ten week long episode of colic, at the end of which it disappears by itself (as it always does). If the parent or doctor had been trying out some new treatment every week for seven days before changing to another, then the treatment tried during the last one of the ten weeks will be found to be "the one that definitely works".

Lactose intolerance is an enzyme deficiency, not a food allergy. A temporary form frequently follow an infection such as gastro-enteritis in a baby. It causes flatulence and diarrhoea that results from undigested lactose reaching the large bowel, where bacteria break it down to lactic acid and hydrogen. The faeces becomes acidic and irritating to the skin, causing a painful and sometimes infected nappy rash. The painful rash causes crying, and this sometimes stops when the irritating nappy is removed, suggesting then diagnosis. Lactose is present in breast milk and in infant formula, so that a baby who has such a problem needs special feeding, lactase enzyme added to milk, or enzyme preparations given by mouth separately from the milk. Lactose intolerance is usually transient.

Regurgitation of stomach contents into the esophagus and throat (gastro-esophageal reflux) has been touted as a cause for infant colic, but it has been shown that while severe reflux can cause crying, the usual excessive crying is rarely caused by reflux. If reflux requires treatment then the treatment is for the reflux as such, not for colic; routine anti-reflux treatment does not reduce irritability and crying.

Excess swallowed gas can cause discomfort, but is rarely a cause for colicky behaviour. Unfortunately substances which reduce surface tension and facilitate burping (for instance simethicone) do not seem to make much difference to excessive crying. On the other hand, the physical contact and soothing that goes along with attempts at getting rid of winds may calm the baby, so that successful treatment of many episodes of crying is not unexpected.

Statistically, the best predictors of complaints of infant colic is the age, parity and socioeconomic status of the mother. This is a somewhat controversial issue, since many parents would take offence at the suggestion that the baby’s crying is the mother’s fault, and the reason for the correlation has not been defined. While there is no doubt that cases of ill treatment can lead to excessive crying, this is fortunately not the normal state of affairs. What is usually the issue is the parents’ ability to cope with the normal crying which they did not cause, rather than them causing abnormal crying. It is the parents’ perception of the meaning of the persistent crying that leads to the doctor’s consultation. This seeking of a medical opinion in the face of uncertainty about her child's well-being is the correct action for a mother, but carries the risk that the crying becomes pathologised – that is, a normal event falsely diagnosed as a disease. The correct treatment in such cases would be reassurance, education and personal and social support for the parents while the baby carries on with his or her normal development. Counseling the parents has been shown to give better results than eliminating cows milk protein and replacing it with a soy product, but the single study comparing the two approaches may have had design flaws, and further studies are needed.

In a list of conditions that may be responsible for the 5% of cases of excessive crying which are due to underlying problems (and therefore not infant colic), the following diseases would be included: corneal abrasion, meningitis (bacterial and aseptic), otitis media, pneumonia, bronchiolitis, gastro-esophageal reflux, strangulated hernia, torsion of the testis or appendix of the testis, intussusception, hair wrapped around the toes or fingers (hair strangulation or tourniquet), and systemic sepsis. These all need professional attention. The mother who is worried about her baby’s crying should never feel inadequate if she seeks professional help in working out why the excessive crying has arisen; there is a reasonable chance that there is a condition that deserves treatment. Colic cannot be diagnosed just on the history of the crying, such as by a telephonic consultation; when a health worker is consulted about this problem, then a physical examination should be done, with a follow-up examination if uncertainty remains.

Management of the difficulties

Treat co-incidental disorders

If poor sleep or hunger contribute to the complaint, then parent training and support is usually required. Simple methods such as swaddling and avoiding over-stimulation can improve the quality of sleep, while the cause for inadequate feeding should be determined and corrected. If treating these factors relieves the crying, the diagnosis of colic was incorrect.

Clearly a medical illness that causes excessive crying should be treated; specific disease need to be treated specifically. An infected nappy rash (impetigo) may require the use of anti-infective agents with subsequent preventative measures being instituted. Gastro-esophageal reflux would dictate special feeding and positioning, as well as antacid therapy. Lactose intolerance may require feeding of special formulas or enzymes. When one considers that the increase and decrease in crying during the first six months of life is part and parcel of normal human development, and that there is a large normal variation in the duration of colicky unconsolable crying during this time, then it is clear that successful treatment of these irritating conditions would not necessary resolve the crying problem. There will be babies where the finding of a treatable illness is a coincidence, and not the reason for the colic. These cases would follow the course of normal colic, where it disappears by four months, in the course of normal development. Furthermore, a condition like gastro-esophageal reflux may require continued treatment irrespective of whether the colic has disappeared.

Feeding change

Adequate feeding is essential. In this regard the technique of allowing the baby to empty a breast before changing to the other breast ensures that a sufficient amount of fats (more abundant in aftermilk) is taken in. This does seem to reduce the frequency of feeds and of hunger crying. Overfeeding, speedfeeding (a South African community nurses' neologism meaning "not allowing rests and pauses during a feed, especially when a bottle is being used"), and failure to burp the baby can cause an increase in crying which may be avoided by a more gentle and relaxed technique. While this crying on its own would not be called colic, any reduction in the total time of crying is a relief to the caregiver.

Allergies to milk can be considered if the baby presents with chronic diarrhoea, vomiting, and failure to gain weight. The parent may know of confirmed cases in the family, and there may be other conditions such as atopic dermatitis and eczema. Onset before four weeks of age would tend to favour colic as a diagnosis, while allergies causing excessive crying frequently become symptomatic after that time. As mentioned before, breastfeeding does not protect against lactose intolerance, and the same is true of cows milk allergy. If the mother takes in quantities of dairy products, the allergens are excreted in breast milk, and the baby ingests cows protein by proxy, as it were. This situation may require that the mother stop eating all dairy products. This is inconvenient, difficult to stick to, and may turn out to be quite expensive. It may be more practical to try an infant feed which contains soy or hydrolysed proteins, or esoteric milks such as goats milk, depending on geographical and financial considerations. A low allergen diet in the mother of the colicky child may reduce symptoms.

Lactose intolerance is considered a transient condition in the majority of cases, with most of these babies probably never even being diagnosed, since their symptoms do not warrant testing or disappear spontaneously (for instance, symptoms of gastro-enteritis lasting slightly longer than expected, but not causing significant morbidity). As far as lactose intolerance is concerned, the lay public rarely considers that a baby could be reacting unfavourably to his own mother’s breast milk.

Conventional Medications

While gastrointestinal spasm has not definitely been established as a major cause for infant colic, the two drugs which have been shown to be consistently effective both act on the smooth muscle of the gut, to cause relaxation. The older drug, dicyclomine, is particularly effective, but it can cause serious complications relating to the nervous system and breathing difficulties, so that it is not recommended for babies younger than six months old. Cimetropium is another anti-cholinergic drug which has been shown to reduce the excessive crying, and does not seem to carry the same risks as dicyclomine. If the developing idea that much of what is pathologised as infant colic is in fact normal development, then simply reducing the tone of the gut on its own would not be predicted to resolve the difficulty of excessive crying. Since both these medications cause sedation and sleepiness, it is possible that the beneficial effect is on the central nervous system. This raises the question of whether it would be wise to use such treatments indiscriminately.

Windiness – both burping and anal flatulence – is a common accompaniment to the symphony of colic. Therefore oral simethicone, a surface tension reducing agent which breaks up bubble formation, has been tried in an effort to help the baby “get rid of the winds”. Trials have shown no therapeutic benefit, which is what would be expected if the windiness were not the primary problem.

The use of oral lactobacillus in feeds shows promise, but at present one should be no more than cautiously optimistic about the applicability of the treatment to colicky babies in general. In a single trial of babies with the diagnosis of colic, responders to lactobacillus treatment exceeded responders to simethicone treatment by an order of magnitude. If the investigators' protocols and analyses were valid, such dramatic results should not be difficult to duplicate, with eventual benefit to many suffering families.

Alternative medications

Plant preparations which have been shown to help for colic include herbal teas and fennel oil emulsion, both of which were effective in double blind trials. The tea described consisted of a mixture of chamomile (Matricaria chamomilla) , vervain (Verbena officinalis), licorice (Glyhrizza glabra), fennel (Foeniculum vulgare), and lemon balm (Melissa officinalis). The dosage for the fennel oil was reported as 5 to 20 ml of an 0.1% emulsion in water, up to four times per day. These treatments are not entirely harmless, and proper doses have not been scientifically determined. Indeed, if they do work, then it means that they possess potentially powerful gastro-intestinal or nervous system actions of unknown nature. A concern is that the volume of tea given may reduce the intake of food (the total volume of fluid given per day works out to be about the same as a single feed), while the chemicals found in fennel oil may cause nervous system side-effects such as convulsions. Once the reason for their efficacy is determined, these herbals would become part of the armamentarium of scientific medicine.

Physical, behavioral and emotional therapies

There are no known physical treatments which reliably eliminate excessive crying in a baby with infant colic. The general recommendation is that any physical discomfort of the infant - conditions such as hunger, cold, an irritating rash, or a wet nappy - should be attended to , and that physical techniques such as touch, carrying and sound should all be employed to settle the agitated nervous system. This may reduce crying by half, but does not eliminate colic.

The oft-quoted studies of the !Kung San in Southern Africa showed that in a culture where babies are carried all day and fed on demand, infant colic is not a problem, even though the crying graph for the first year of life follows the same pattern of peaking at six weeks and stabilising at four months as in Western countries. Efforts to reproduce those circumstances and results in infants with colic have met with little success.

Canadian pediatrician Ronald Barr has developed a new approach to the problem, basing it on the likelihood that colic is simply one extreme of normal, and that the problem lies rather with the response that uninterrupted crying evokes in caregivers. As part of an effort to reduce parental frustration and impulsive acts towards the baby, he has coined the acronym PURPLE crying, for the characteristics of this normal stage of human development. The intent is to educate and help caregivers remember that the colicky activity is neither selfish, nor maliciously intended, nor a sign of disease, nor easily dampened by even the best of care, thereby possibly reducing the incidence of the shaken baby syndrome. This challenges the idea that the crying indicates that “something is wrong” for which which “something must be done”. An appropriate response would be prompt, appropriate and caring; the idea that leaving a baby to cry has an educational or training value is unscientific and without any merit at all - to think that babies of three months old can be spoilt is equally wrong. Such a response includes touching, carrying, rocking, singing, talking to, swaddling and tucking to settle the baby. It emphasises the wisdom of leaving the infant in a safe situation when the crying becomes intolerable for the caregiver, rather than losing control of impulses.

PURPLE Crying

P = Peaks at around two months of age.

U = Unpredictable, often happening for no apparent reason.

R = Resistant to soothing.

P = Pain-like expression on the baby's face, even without any source of pain.

L = Long bouts, lasting 30 to 40 minutes or more.

E = Evening crying.

A multimodal intervention that teaches similar techniques has been tried in Australia, with promising results. It employed multiple strategies in mothers and children who were admitted to a care center. The teaching of techniques of settling the baby, as well as maternal education, practical help and counselling lead to a significant decrease in problems with colic, both during the stay and on follow-up a month after discharge. In keeping with the evolving concept of colic being at least as much of a problem for the caregivers as it may be for the baby, attention is increasingly being given to educating and supporting the mother and family. Increased sensitivity to, early treatment of, and extended support for parents with coping difficulties, depression and anxiety states after the baby's birth is advocated.

Consequences

Infant colic has no known long-term physical consequences for the baby. To prevent short-term consequences, the first priority is to find and treat other potentially harmful disorders which may look (or sound!) the same. The second is to manage the extreme frustration and emotional distress which the inconsolable crying of a child can cause in the parent. The incidence of the Shaken Baby Syndrome follows that of the normal increase and reduction of crying accurately, although it shows a lag of about a month. The lag may be explained by the fact that the abuse statistic is generated at the time that the condition is diagnosed, not the time of first injury. Persons outside of the family need to be aware of the stress which the excessively crying baby can place on a family, and suitable steps taken enabling parents to cope.

It appears that excessive infant crying can have consequences for long-term psychological well-being, presumably based on the disturbed mother-baby relationship which develops. Conversely, the irritability of some colicky babies may simply be the early signs of the later difficulties. These irritable babies have an increased disposition to behavioural and sleep difficulties as preschool toddlers, but this has not been followed through to adult age.

Conclusion

Infant colic is not an inconsequential disorder, it may have disastrous effects on the baby and the family. While the gut theory of colic remains accepted as viable, and supported by treatments and research aimed at relieving gastro-intestinal problems, the opinion that infant colic is also a normal human developmental stage has gained ground. Education about how to cope with the situation and utilise extended family help as well as social services, combined with a trial of dietary modification, may be better medicine than initially trying medications for the baby. Such an approach seems to be far better than brushing off the complaint of infant colic as unimportant, and is supported by an extensive literature on the subject, both popular and professional.