(1)
Department of Child Health, University of Missouri, Columbia, MO, USA
Chapter Outline
Definition
Epidemiology
Differential diagnosis
The pain hypothesis. The neurodevelopmental hypothesis
The subsidence of colic
Management of Infant Colic
Persistent Colic
Why do I include a chapter on infant colic in a book on functional gastrointestinal disorders when I don’t believe that colic is an abdominal, much less a gastrointestinal, phenomenon? [1, 2]. It’s included because the more intractable cases are referred for gastroenterological consultation [3] based on the widespread, traditional belief that the infant with colic cries because it is experiencing pain and because, in its more severe presentations, it causes unbearable distress in parents who had expected their baby to be easier to understand, to comfort, and to love.
Definition
There is no universally accepted definition of infant colic [4] because there is no agreement on its nature or cause. The definition used in the present discussion is: crying during the first 3 months of life for 3 or more hours per day on 3 or more days per week in infants who do not suffer other conditions that may cause prolong crying, e.g., organic diseases, hunger, or neglect [5–7]. This definition is heuristic, with elements chosen for the purpose of defining a population to be studied; it is not based on data from naturalistic observations.
Colicky crying is best considered within the context of “normal” infant crying during the first year. All infants cry. Brazelton’s data [8], confirmed 28 years later by Barr [9], demonstrated what is referred to as “the crying curve” (Fig. 5.1).
Fig. 5.1
Hours of crying and fussing per day plotted for 15 normal infants from 3 to 12 weeks of life. (Ronald G. Barr)
During the first 3 months, normal infants generally cry more than at any other time in their lives. Crying increases during the first month, peaks during the second month, and tends to decline thereafter. It tends to be greater in late afternoons and evenings [8, 9]. This temporal pattern of crying by infants in general is similar to the usual course of crying by infants with colic. The question remains: is colicky crying etiologically different from the crying of non-colicky infants, or is it the same, but at the upper end of the normal crying curve? Surprisingly, the frequency of onset of crying bouts in colicky infants is similar to that of infants in general [8], but the duration of their crying bouts is longer and they are less consolable [10]. Typical colicky crying is high pitched. Bouts may begin suddenly, without warning, and have a rapid crescendo towards peak intensity, accompanied by clinched fists, drawn up knees, and increased muscle tone [11].
In mice and humans, agitated babies become calm and quiet when comfortably held by their mothers who move about [11-a]. The evolutionary advantage of this physiological response may possibly be the improved chances of survival by mother-child couples while running to escape predators; fussy infants that become quiet and relaxed are more easily carried and concealed.
A diagnostic feature of colicky crying is the effect of soothing maneuvers; rhythmic rocking while patting the baby’s back would probably not quiet crying caused by hunger or pain, but does calm colicky crying for as long as the maneuver continues or sleep supervenes [12]. Calm reverts to fussing when the baby is put down, but is restored when the baby is picked up and rocked again. This “on-off-on-off” crying response can be repeated ten or more times during a crying bout [13]. Rocking is more likely to be effective when the rocker is relaxed, unhurried, and empathetic [14].
Epidemiology
Colic is virtually unknown in some undeveloped and traditional societies in which an infant’s cry is treated as an urgent signal and responded to immediately [10]. Industrial societies provide less cultural reinforcement of rapid, instinctual parental responses to the crying of young infants and their crying is more likely to be viewed as a medical problem [15, 16]. Although estimates of the prevalence of colic vary between 9 and 40 % [17, 18], it is generally reported to occur in about 20 % of infants [11, 19] Colic affects infants of all socioeconomic classes equally, boys as often as girls, and infants who are breast fed as often as those who are bottle fed [18–20]. It is unrelated to a family history of allergy [18, 19]. There is conflicting evidence regarding the effects of prolonged labor, forceps delivery, and epidural anesthesia as predisposing factors to colic [21–23]. These events may have transient or persistent noxious effects on the central nervous system which may cause intractable crying of organic etiology, different (by definition [5]) from the colicky crying of well babies.
Some infants with intrauterine growth retardation are born with diminished muscle tone, activity, and social responsiveness; they are unusually quiet and prefer to be left alone during the first 2 weeks. Thereafter, they may have long bouts of inconsolable crying which have been attributed to “neurophysiologic hypersensitivity” [24]. The relevance of this syndrome to ordinary “3 months colic” is unknown.
Differential Diagnosis of Prolonged Crying in Young Infants
Persistent and recurrent crying in early infancy may be a sign of cow’s milk protein intolerance [25–28], reflux esophagitis [29], fructose intolerance, infant abuse, congenital central nervous system abnormalities, infant migraine, urinary tract infection, anomalous left coronary artery, intestinal volvulus, and other illnesses [30]. However, diseases that may be mistaken for infant colic usually lack its typical temporal pattern and temporary responses to effective soothing maneuvers [31, 32]. Whereas the diagnosis of organic causes of persistent crying may be confirmed by technologic tests, there is no test by which infant colic can be ruled-in or ruled out.
Is colicky crying essentially different from that of the 25 % of “normal” babies who cry more than 2 and 3 h per day? [8, 11]. Or is it simply crying of the highest intensity, acoustically indistinguishable from crying caused by acute pain, hunger, or loneliness? [30–32]. Are the activities that accompany the crying of colic specific to colic or are they nonspecific motor accompaniments of intense crying of any cause? [13].
The Abdominal Pain Hypothesis vs. The Neurodevelopmental Hypothesis
Research on infant colic has taken two main paths: one is based on the presumption that infant colic is caused by gastrointestinal pain; the other path is based on the presumption that colicky crying has a neurodevelopmental basis, not caused by pain or organic disease of any kind—that (in the words of Ronald Barr) “colic is something that infants do, rather than a condition they have” [9].
Research based on the presumption that colic is due to abdominal pain has shown statistically significant physiologic differences between populations of colicky infants and infants who do not cry excessively. Whether these physiologic characteristics of colicky infants cause their crying, result from crying, or are produced concurrently by whatever causes the crying, is an unsolved question [1, 11, 24, 25, 32–39]. Suffice to say that none of these abnormalities explain the temporal pattern or the effectiveness of soothing measures that would not be expected to relieve abdominal pain. And none have thus far led to an etiologic “cure” for colic [25, 34, 37].
The neurodevelopmental hypothesis is ontological. The fetus is in an almost constant steady state. Once out of the womb, however, the neonate loses its unchanging environment and is accosted by new experiences, such as hunger, thirst, visual stimulation, environmental excitement, temperature changes, and tactile experiences, to name a few. Once out of the womb, when the neonate experiences hunger, it reacts by making the transition to the feeding state. It is hypothesized that “colic” is the behavior of infants who have difficulty making transitions from one state to another [15]. Difficulty in state transitions might cause a baby who is crying because it is hungry, to suck a few times when put to the breast, then pull away, arch backwards and fuss. The fussing rapidly intensifies into “colicky” crying which makes feeding temporarily impossible and can persist, even though the infant is still hungry. Similarly, a sleepy baby might be unable to make a smooth transition from being awake but sleepy, to falling asleep.
Colicky infants tend to be more reactive to sensory stimuli as well as more difficult to soothe [40]. Therefore, removing distracting stimuli from the environment may make state transitions easier. This is exemplified by the infant whose night time feedings were made easier while being gently carried about in a dark, quiet room.
Although the duration and intensity of an infant’s crying can be modified by soothing techniques, the pattern of crying during the first 3 months, referred to as “the normal crying curve,” cannot be modified [4, 9]. As stated by Miller and Barr, “…crying—including that which is said to be typical of colic—may be better understood as a behavioral state that is nonspecific to any one of a number of causes. Rather, those infants whose crying is labeled as colic may represent individual irritability and difficulty with state regulation, in which the cry state is more readily provoked and intractable once established” [4].
How Does Colic Subside?
At about 2–3 months of age, infants become more attentive and socially responsive. This developmental shift accompanies their acquisition of an awareness of the distinction between “self” and “other” [41]. They become better able to sooth themselves, more adaptive, more able to interact with, and give pleasure to their caregivers [4, 41]. These developmental shifts occur at about the age that colic subsides. One hypothesis for the disappearance of colic is that the developmental advances that occur at 2–4 months enhance the infant’s ability to manage state transitions that enable it to more effectively self-sooth and evoke desired behaviors from caregivers. These new abilities provide the infant with options for tension resolution other than crying. Developmental advances are smoother and accompanied by less crying if the infant’s temperament is easy, the mother is caring, intuitive, and self-confident, and their dyadic relationship proceeds with smooth reciprocity [42–44].
Parents may bring to the colic syndrome difficulties of their own which may present the clinician with therapeutic opportunities. Emotional tension and depression during pregnancy, adverse experiences during labor and delivery, and postpartum depression are associated with a greater prevalence of colic [22, 45–48]. Excessive crying may exacerbate maternal depression or anxiety and distort the mothers perception of what might actually be ordinary crying behavior [6, 45–49].
Management
Parents who view their infant’s colic as a temporary, benign pattern of behavior don’t seek medical attention or, if they do, need only be effectively reassured that their baby is well [50]. However, colic can present as a crisis when the crying seems uncontrollable, when all attempts at “curing” the infant have failed, and when parents feel overwhelmed, angry, and guilty of unavoidable negative feelings towards their infant [44, 51].
The goal of management should not be to abolish the crying; nothing of what is known about the physiology of colicky infants has led to a “cure.” Antispasmodics, sedatives, simethicone, formula changes, fiber supplements, and other measures based on the assumption that the crying is due to gut pain have produced little or no benefit beyond their placebo affects in most infants [38, 52–54]. If there is a plausible possibility of milk intolerance or acid reflux as causes of crying, a time–limited therapeutic trial of a hypoallergenic formula or acid suppressant medication is warranted. Relief in such cases should become apparent within 48 h. Otherwise, management should aim at the goal of helping parents through the difficult early months of their normal infant’s development [55, 56].
Less effective management strategies involve trying a succession of harmless formulas and medications of little or no efficacy [1]. Colic is a time-limited condition, highly responsive to placebo [57]. Sooner or later, one of the trial measures will “work.” Sequential prescriptions give parents “something to do” in the meantime. The advantage of this approach is that it requires little of the clinician’s time. One of its disadvantages is that treatments carry with them the implication that something “wrong” is being treated, and this iatrogenic stigma is reinforced when whatever is “wrong” is “cured” by a medical prescription [56]. Another disadvantage is its impact on parents whose hopes may turn to anxious despair each time a “treatment” fails.
The following elements of management are derived from interventions employed during my experience with about 350 infants referred for what turned out to be symptoms of infant colic that were refractory to previous management.
Acknowledge the difficulty and importance of their problem . Previous clinicians may have told them that their infant has colic, that it is not serious, that it will go away, and that all that they need to do is be patient. If the parents had been able to accept such statements, they would not have come for another opinion. They need to hear that, regardless of what the term “colic” implies, it can cause great suffering and disruption of family life [43, 47, 51, 58].
Sampling their experience. With luck, the baby will have one or more crying bouts during the consultation. This gives the parents the satisfaction of showing the clinician just what they’ve been experiencing. It allows for observation of how the parents respond to the crying and a chance to clarify the differences between hunger crying and colicky crying—a distinction parents who have adhered to a feeding schedule may have trouble appreciating. If the baby is fed, we can see how he feeds and whether feeding is satisfying or tension-producing in the infant and parent. If feeding doesn’t calm the baby, we can observe how the parents go about trying to soothe their infant and how they interact with each other.
Finding and modeling calming methods. A crying bout is an opportunity for the clinician to model comforting procedures, e.g., rocking and patting, and responding quickly before the bout gains momentum. Successful modeling of soothing procedures should be done as a diagnostic procedure to discover what is effective, being careful to avoid the false implication that the clinician is a more competent caregiver [59].
Dismantling the pain theory is essential to management . If the parents cannot see their child’s crying as anything other than pain behavior, then, regardless of how much we tell them that colic is safe and will soon subside, they won’t be satisfied. Competent parents cannot put up with watching their infant suffer what seems to be pain that they feel powerless to relieve. They want relief and insist that it be given immediately. (Demerol has been recommended for otherwise intractable colic, and the use of a narcotic analgesic would be humane and appropriate if one accepts that “colic is pain” [60].) The possibility that colicky crying might not be due to abdominal pain is counter-intuitive. Parents may have difficulty relinquishing the pain paradigm [56]. Up to this point they may have had no other explanation for the crying, and to experience their baby’s crying and not have any notion of its cause is to suffer existential anxiety. Good communication skills enable the clinician to make the developmental paradigm believable. Parents would probably feel better if they believed that their infants’ crying is part of normal development rather than an abnormal affliction [61]. Satisfying their need to feel better about their infant helps them shift to a less troubling explanation of why their infant cries.
Teaching about the effects of stress on caregiving. Parents’ feelings of ineffectuality may intensify when the clinician is successful after their efforts failed to quiet their baby. To counteract such feelings, I tell of an experience I had as a young pediatrician providing weekend coverage for a senior colleague.
I received a telephone call at 2 PM one Sunday from a woman with a 6 week-old baby who had been crying for 8 h. Her husband was away on a business trip and couldn’t be reached. She was alone with no one to help her. After questioning her about the infant’s physical well-being, I concluded that the crying was colic. I advised her to rock the baby. If this didn’t calm him, she was to call me back.
I received her 2nd call at 7 PM. She had rocked the baby for almost 5 h with no success. After another round of questions, I remained convinced of my original diagnosis and advised her to try all of the other soothing maneuvers I could think of. Her 3rd call came at 3 AM. None of my recommendations had helped. The baby was still crying. However, this time the answers to my questions now suggested the possibility of meningitis. I eschewed further advice-giving and immediately drove to her home.< div class='tao-gold-member'>Only gold members can continue reading. Log In or Register to continue
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