Colic is one of the most distressing conditions otherwise ‘healthy’ infants present with. The sudden onset of prolonged crying can be frightening as well as upsetting for the parents, and inevitably by the time they seek professional advice many feel quite helpless. This article reviews the latest information and research into the condition to help you make informed and effective recommendations.

Introduction

Colic is one of the most distressing conditions otherwise ‘healthy’ infants present with. The sudden onset of prolonged crying can be frightening as well as upsetting for the parents, and inevitably by the time they seek professional advice many feel quite helpless. However, colic is one of the most common infant feeding problems in infancy¹ with estimates suggesting that 5-20% of infants suffer¹, depending on the definition used for colic.

There is little to suggest which babies will suffer from colic since it is not discriminatory – it appears to affect both sexes, all socio-economic groups and both breast and bottle-fed infants². Those caring for a baby with colic, however, usually share one commonality – a desperate need to ease the symptoms as quickly as possible. This article reviews the latest information and research into the condition to help you make informed and effective recommendations.

Clarifying it is colic

For clinical purposes, colic is defined as ‘repeated episodes of excessive and inconsolable crying in an infant that otherwise appears to be healthy and thriving’³. However, researchers tend to use the more specific Wessel Criteria⁴, whereby ‘the child cries, for no obvious reason but with full force for more than 3 hours a day on 3 or more days a week, for a minimum of 3 weeks’.

The key signs to look out for are^5-6:

• high-pitched crying which starts spontaneously and nothing the parent does seems to help
• crying which begins at approximately the same time each day, often in the afternoon or evening
• onset within weeks of birth, often continuing until around the age of 3 to 5 months
• the baby may draw their legs up when they cry
• the baby may clench their hands
• their face may look flushed

The child should otherwise appear healthy, with no other diagnostic symptoms such as⁷:

• abnormal urine
• diarrhoea or blood in the stools
• fever
• abnormal tympanic membrane
• signs of physical trauma

Potential causes

Despite extensive research, the cause of colic is undefined, and it is likely to be multifactorial. The following may be contributory factors:

Immature gut – Immature intestines have been found to be more permeable⁸ and may allow large molecules such as cows’ milk protein and/or lactose to pass through and be absorbed rather than broken down⁹. If the lactose present in milk (breastmilk or formula) cannot be digested due to a lack of the enzyme lactase, it can ferment causing the gas and wind that typify colic. Meanwhile the pressure generated by lactose and lactic acid in the stomach can produce an influx of water, leading to a swollen abdomen and acidic diarrhoea.

There also appears to be a link between gut hormones involved in the regulation of gut motility and infantile colic, since high levels of motilin and ghrelin, hormones secreted by cells in the small intestine, may contribute to the intestinal hyperperistalsis and cramping so commonly associated with the condition¹⁰.

An immature gut may also be associated with gastro-oesophageal reflux disease. Although the symptoms can appear to be similar, the two should not be confused.

Intestinal gas – In addition to the fermentation of undigested lactose, there are other reasons intestinal gas can build up causing abdominal distention and intestinal spasm^11-12. Perhaps the most obvious of these is the ingestion of excess air while feeding, or inadequate burping afterwards inhibiting the release of trapped air. However, new research also suggests there could be other pathophysiological reasons for the gas, such as differences in the gut microflora of babies with colic.

Gut microflora – Research is increasingly pointing to key differences in the gut microflora of babies with colic. For example, they appear to have higher levels of gas-forming coliform bacteria, (e.g. Escherichia colli¹³) and lower counts of intestinal Lactobacilli^14-15. More recently, Klebsiella has been found to be disproportionately present in the intestines of the babies with colic (whether breast or formula fed) and this organism may be responsible for an inflammatory reaction comparable with that of inflammatory bowel disease¹⁶. Colic may therefore be a precursor to other gastrointestinal conditions such as irritable bowel syndrome, coeliac disease and allergic gastroenteropathies, although more research into this is required.

Food allergy – There is increasing evidence that cows’ milk proteins play an important role in the pathogenesis of infantile colic^17-18. If cows’ milk allergy (CMA) is suspected, the diagnosis should be confirmed promptly as in very severe cases it can lead to anaphylactic shock if left untreated.

Decreased contractility of the gall bladder – There is evidence to suggest hypocontractility of the gall bladders of colicky infants may be due to a disturbance in cholecystokinin secretion¹⁹.

Exposure to cigarette smoke – The prevalence of colic is approximately twice as high among infants of mothers who smoke¹⁸ and may be attributed to elevated motilin levels that lead to intestinal spasm^20-21.

Parental behaviour – Negative psychological factors in the parents, such as anxiety and stress, have been associated with increased incidence of colic, while overstimulation of the child and fussing appears to make the problem worse^23-25.

Treatment pathway

Parents of babies with colicky symptoms will be looking for immediate relief, as well as guidance on how to remedy the problem.

From a clinical perspective, the NHS recommend an upright feeding position and adequate burping post-feed, to hold the baby during a crying episode or to use a faster flow teat with larger or more holes. Anecdotal strategies for relief from colic (outlined on the downloadable link), include the use of ‘white noise’, motion (from either the car, buggy or a baby swing), or simply carrying the baby around, although care should be taken to not overstimulate the baby.

The following is taken from the current treatment pathway recommended by the NICE Clinical Knowledge Summaries (last updated November 2014)²⁶.

The most useful intervention is advice and support for parents and reassurance that infantile colic will resolve. Only consider trying medical treatments if parents feel unable to cope despite advice and reassurance. The options for medical treatments are:

• A 1-week trial of simeticone drops (such as Infacol® drops).
• A 1-week trial of lactase drops (such as Colief® Infant Drops).

Only continue treatment if there is a response (such as the duration of crying shortens). If there is no response to one medical treatment, consider trying another.

Nutritional intervention

Given the growing body of evidence to suggest differences in gastrointestinal pathophysiology of colicky babies, along with the withdrawal of the pharmaceutical remedy Dicylomine following safety concerns, nutritional interventions may be a useful approach.

Although not mentioned in the current NICE CKS suggested treatment pathway, there is growing clinical support for the inclusion of pre/probiotics in an infant’s diet^27-31. Given that these can help address certain gut microflora imbalances often associated with colic it is reasonable to suggest that they may be considered for inclusion in future recommendations.

Breastfed babies

Addressing intestinal issues

To help combat the issues associated with an immature digestive system and differences in gut microflora, simeticone and/or lactase drops are often given (despite a lack of evidence to support the former). However, certain probiotics may prove preferable since, for example, Lactobacillus reuteri, when given in a supplement form, has been found to help shift the intestinal ecological balance from potentially harmful to beneficial, addressing associated gastrointestinal issues in doing so^27-28. For example, when breastfed babies were given drops of either a probiotic or simeticone once a day, 95% of the babies taking the probiotic cried less after 28 days, compared with only 7% of the babies taking simeticone²⁹.

Addressing possible dietary sensitivities

As colic is not an allergy, it is important to reassure the mother that the baby should be able to tolerate dairy in later life and that this is merely a transient phase. If a test does confirm CMA, which is diagnosed in only 2-7.5% of infants in the UK³⁰, the prognosis is good, with an 85-90% remission rate at 3 years of age³¹.

Bottle-fed babies

Addressing intestinal issues

As with breastfed babies, the first line of intervention for bottle-fed babies has traditionally been to try simeticone or to add lactase drops to the feed half an hour before intake.

In addition, research has shown that adding prebiotic oligosaccharides (prebiotic OS) to infant milk has been found to be particularly beneficial for all formula fed babies^32,33. Babies fed a formula containing a blend of prebiotic OS in the first 6 months of life experienced a significantly reduced incidence of allergic symptoms, infections and need for antibiotics over the next 2 years³⁴. This may be because prebiotic OS work by decreasing the presence of pathogens in the gut flora and increasing the growth of friendly bacteria such as Bifidobacteria and Lactobacilli^35-37 and so can be beneficial for colicky babies for whom gut flora has been a contributory factor. Colonic gas may also be a cause of gut pains. In one study a formula with less lactose reduced the air released by colonic fermentation theoretically helping to reduce excess gas in the colon³⁸.

Addressing possible dietary sensitivities

Unless there is evidence of severe CMA, multiple food protein intolerance or other conditions where an elemental diet is recommended, formula with reduced allergenicity may be considered to help address colicky symptoms.

Such formulas are available as either whey or casein based and the proteins partially or extensively hydrolysed i.e., the proteins have been partially or extensively broken down into smaller peptides to improve digestibility and reduce allergenicity. Some of these products may only be available on prescription.

The body of evidence supporting the use of partially hydrolysed formula in the treatment of colic is growing all the time^5,39. In a study of 175 infants randomly assigned to 4 different intervention groups (massage, sucrose solution, herbal tea and hydrolysed formula) or to control, the greatest reduction of significant crying was reported in the hydrolysed formula group⁴⁰.

Extensively hydrolysed formulations are sometimes referred to as hypoallergenic formulae because they tend to be prescribed for CMA and/or complex, multiple food intolerances and malabsorption. However, there is evidence (outlined below) suggesting that babies who haven’t been diagnosed with an allergy, but who are suffering from digestive discomfort and colicky symptoms anyway, could benefit from partially hydrolysed based formula^40-42as it is generally easier to digest than normal infant formula on account of the broken down (partially hydrolysed) protein.

Formula for the dietary management of colic in bottle-fed infants

In light of the distressing nature of colic and the lack of effective treatments other than parental reassurance there has been increasing interest in the role of nutritional factors in the management of this problem. As a result formulas have been developed to assist in the management of colic in bottle-fed infants.

Research into their benefit is ongoing but in an initial study of 604 infants, a partially hydrolysed milk formula was found to reduce the frequency of crying episodesby 50% for 79% of the subjects after 14 days, with the greatest reduction occurring at 7 days⁴¹.

This partially hydrolysed milk formula contains significantly less lactose than standard infant milks. It is also formulated to aid the absorption of fat and calcium and to produce softer stools. This is achieved by the inclusion of special fat blends that contain relatively high proportions of palmitic acid in the beta position⁴³. To help modulate gut microflora, this formula also contains a patented mix of prebiotic galacto- and fructo-oligosaccharides that have been found to increase the numbers of beneficial gut bacteria^35-38,40.

Soy

Although there had been evidence to suggest that soy formula may be beneficial in addressing colicky symptoms⁴² it is not recommended by the Department of Health for UK infants under 6 months of age.

Summary

To summarise, infantile colic, defined as excessive crying in an otherwise healthy baby, is a distressing phenomenon. Although definitive answers remain elusive, the latest research increasingly highlights differences in the gastrointestinal tract of babies who present with colic, and notably to an immature digestive system and gut microflora.

Since the withdrawal of dicyclomine, there appears to be a growing case for nutritional interventions such as the use of partially or extensively hydrolysed formula, maternal diet adjustment (if breastfeeding), and the addition of certain pre/probiotics – notably prebiotic oligosaccharides (OS) and Lactobacillus reuteri – in order to address imbalances in the gut microflora.

While many parents provide anecdotal evidence of soothing strategies, ranging from white noise to motion, the only single treatment that appears to work for most people is time. The reassuring news for parents is that children with colic tend to grow out of it by around 4 to 6 months of age and suffer no lasting ill effects.

About the author

Lisa Chick is a professional health writer and researcher for pharmaceutical and healthcare organisations