This is of course not helpful, or even satisfactory, to parents understandably upset by their infant’s Colic. They expect the physician to know what’s causing it, and want an effective treatment to be prescribed! An honest explanation that no proven treatment exists is easily misinterpreted by parents as reflecting a lack of caring on the part of the physician. Knowing this, many otherwise good physicians unfortunately give in and are untruthful about our ignorance & impotence with respect to this problem. Instead, they resort to perpetuating dubious or disproved theories and/or to prescribing therapies that are at best unproven, are known to be no more effective than placebo, or occasionally may even be dangerous.
Theories of Colic: Pain
It is quite natural to think that a colicky baby must be suffering from some sort of pain. Indeed, every parent or grandparent who has taken care of such a baby for thousands of years has thought so. The very word “colic” is derived from the ancient Greek word for pain. Other medical “colics” (renal colic, biliary colic) refer to very painful diseases (kidney stones, gall stones). We know from scientific studies, however, that colic is not due to pain. Modern pain experts have learned how to measure pain on a physiologic level using brain waves, hormone levels, and other physiologic measures. Such measures have been used to prove such things as the fact that newborns do feel pain, no different than adults do, during such procedures as needle sticks or circumcision. When colicky infants are hooked up to such monitoring devices, however, they display a very different physiologic pattern. It looks nothing like pain! It looks more similar to anger! What that means, we can only speculate…
Theories of Colic: Gas
The idea that colic must be in some way related to gas comes from the nearly universal observation that infants with colic pass a lot of it. Sometimes this is in the form of flatulence, other times it is in the form of excessive burping. Studies seem to indicate, however, that infants pass gas because they have colic – they do not have colic because they have gas. The most direct evidence for this are studies in which infants without colic were made “artificially gassy” using diet or benign medications. These babies passed a lot of gas as a result, but they did not cry more. Further evidence against the gas theory of Colic comes from studies of “gas drops” (Mylicon, Phazyme). Whether these drops work or not depends what you look at. If the study focuses on the amount of actual gas passed, the drops are effective in reducing gas. However, if the study focuses instead on total crying time and severity of Colic, gas drops have been shown to be no more effective than placebo. Today we believe that babies who cry a lot swallow air when they are crying – what goes in must come out. The colic explains the gas, not vice versa.
Theories of Colic: Allergy
One gastrointestinal problem that does have some association with Colic is food allergy. This association is mild, however, and only applies to a minority of newborns with Colic. Babies with food allergy may initially seem to have Infant Colic – however they will usually develop other symptoms of food allergy within a few weeks time. These other symptoms can include eczema, spitting up, diarrhea, bloody stool, and a failure to grow. The development of these other symptoms makes the diagnosis of food allergy easy once they occur – and they do eventually occur in almost all babies who have food allergy. While some babies with Colic (the ones who are really in the early stages of developing food allergy) do respond to a switch to hypoallergenic formula, this is but a small percentage of all infants with Colic. Because hypoallergenic formulas are very expensive and not as nutritionally complete as the more standard infant formulas, however, switching colicky infants to them before they have developed other signs and symptoms of allergy is not generally recommended.
Theories of Colic: Real GI Issues
Gastroesophageal Reflux can cause abdominal pain in a newborn, but is usually accompanied by abnormally severe spitting up and sometimes coughing, gagging, and poor weight gain as well.
Lactose intolerance is an inability to digest the main sugar in milk. It is NOT a food allergy and bears no relationship to food allergy. It tends to run in families and can sometimes present initially as Infant Colic. However, newborns with Lactose intolerance tend to have other symptoms beyond crying – particularly spitting up and poor growth.
Likewise, simple Constipation can also present with Colic – but usually this is obvious because the child has firm stools. Thus, both Lactose Intolerance and Constipation are usually fairly easy to recognize, and respond to simple interventions such a change in formula or a stool softener. They therefore should be thought of separately and not lumped together with Infant Colic.
Theories of Colic: Other GI Concerns
Some parents blame dietary iron for Colic, or believe that some other aspect of food “tolerance” (besides allergy) may be at work. Many physicians encourage this by engaging in random formula changes trying to treat Colic. However, the amount of iron in breast milk or even iron-fortified formula is NOT enough to cause stomach upset. Studies have shown that switching formula (in any direction) in the absence of clear clinical signs of Allergy, Constipation, or Lactose Intolerance is no more effective than placebo in curing Colic. Many other aspects of gastrointestinal function in infants with colic have been studied as well. Such infants are no more or less likely than other infants to grow normally. They are no more or less likely than other infants to be able to digest common foods. The entire GI tract of colicky infants who have died from other causes (e.g. motor vehicle accidents) have been studied “from stem to stern” under electron microscopes and no difference between them and other normal infants has been found. Children with a history of Infant Colic have been followed through childhood and out into adulthood. Their rates of later GI diseases (such as Inflammatory Bowel Disease, Irritable Bowel Syndrome, Ulcers, Gallbladder Disease, Liver Disease or Pancreatic problems) are no different than the population “at large” or from individuals without a history of Colic.
Theories of Colic: Psychosocial
Another theory of Infant Colic, which held some popularity in the late 70’s and early 80’s, was that it had something to do with poor maternal-infant bonding. This was an era when much research on infant bonding was being done and we understood more and more about this phenomenon. It seemed logical that colicky infants were having difficulty with this process. Mother-infant pairs including both colicky and non-colicky infants were observed in many psychological research protocols and it was found that there was no correlation between the quality of infant bonding and daily total crying time. Indeed, some very poorly bonded and even neglectful parents had very quiet babies while some of the most attentive and well-bonded parents had the most colicky babies. Indeed, more generally, it was found there was really no correlation between parent behavior towards the baby and Infant Colic whatsoever .
Theories of Colic: Temperament
Another idea has been that Colic is an early expression of a “difficult” personality. Babies who have had Infant Colic have been studied later in life. It has been found that there is no correlation between a history of Infant Colic and I.Q., personality, school success, juvenile delinquency, or a whole host of psychological difficulties including depression, anxiety, and personality disorders. In short, Infant Colic has nothing to do with psychology.
Theories of Colic: Neuro-development
This is the theory that we believe here at Children’s Medical Office. It is perhaps the least well-known, but it is the most logical and scientifically appealing theory about Infant Colic (and the only one that hasn’t been completely disproved). It holds Colic to be a phenomenon of neurologic immaturity. It has been observed that infants with Colic are more easily over-stimulated than other babies. Once they become “worked-up”, they have a much harder time being “brought back down” by themselves or others. State-control is the neurological skill felt to be relatively immature in these babies. This is the ability of a person to maintain a comfortable mental “state” (such as being awake & alert or soundly asleep) and the ability to transition out of an “uncomfortable state” in the direction of a more comfortable one (e.g. someone who is “drowsy” either tries to fall asleep or wake up, someone who is crying tries to soothe themselves). This ability, like memory or language, gets better with age. Most adults are far better at it than children. Older children are better than younger children. Some newborns are better at it than others.
The neurodevelopmental theory is supported by several observations. The first is that all babies with Infant Colic outgrow it, usually by 4 months of age. The second is soothing strategies which involve a good deal of stimulation (such as rocking, singing, talking, feeding, changing diapers, etc.) usually are counter-productive for colicky babies. In contrast, strategies which involve reduction in stimulation (swaddling, placing in a dark room, “white noise”) tend to be more successful. This theory has led to the development of a device known as the “Sleep Tight” which combines a vibrator with a monotonous tone and attaches to the crib simulating a car cruising at 55mph on the highway. The makers of this device sell it with a money-back guarantee to cure colic (it can be obtained by calling 1-800-NO-COLIC or visting www.colic.com). In our experience, this works for many babies, but not all. It has the advantage over other potential therapies of being harmless, at least. Current proponents of the neurodevelopmental theory propose relatively benign treatments such as the Sleep Tight, swaddling, and avoiding over-stimulation.