Approach to the Child with a Functional Gastrointestinal Disorder

Biomedical Model

The biomedical model has been the dominant model for understanding disease. The biomedical model makes two assumptions: (1) any symptom can be traced back to a single cause, and (2) every symptom is either “organic,” meaning there is identifiable and objectively defined pathophysiology, or “functional,” meaning without objectively defined pathophysiology. This dualistic approach implicitly places “organic disease” in high esteem.

The biomedical model works well for acute conditions like bone fractures, appendicitis, or nephrolithiasis, but not so well when there are chronic problems such as headaches, abdominal pain, or chronic fatigue.

Biopsychosocial Model

The biopsychosocial model, proposed by Engel in 1977, is an alternative to the biomedical model. In the biopsychosocial model, the goal is to understand and treat illness –the patient’s subjective sense of suffering–rather than confining the diagnostic effort to finding disease. Physicians who engage the biopsychosocial model recognize that symptoms may develop from several different influences, not just disease. Symptoms may stem from normal development (e.g., infant regurgitation), psychiatric disease (e.g., somatic symptom disorder, conversion disorder, factitious disorder imposed on another), the impact of culture and society (e.g., a man with chest pain ignores the symptom because he carries no health insurance), and functional disorders, in which symptoms are real but there is no easily discerned disease. Examples include tension headache, fibromyalgia, IBS, and functional dyspepsia. Several conditions may occur in the same patient. For example, Crohn disease may occur together with IBS, so the patient may experience intolerable abdominal pain and diarrhea even when Crohn disease is in remission. Rumination syndrome (a functional disorder) may coexist with social anxiety (a psychiatric disorder), resulting in a person who cannot leave the house because of “vomiting.” Fig. 7.1 shows psychosocial and biomedical factors that share an interactive relationship in the clinical expression of illness and disease.

The Rome IV committee has introduced a new, formal way to describe the biopsychosocial features of illness called the multidimensional clinical profile (MDCP). This clinical profile provides a template for the psychosocial aspects of the illness that are often overlooked in clinical practice but contribute to the overall suffering in every patient. It also explains the enormous variability in phenotypes. For example, some patients with diarrhea-predominant IBS have infrequent and mild symptoms while others have severe pain, emotional distress, and physiological disturbance. Treatment also varies based on these individual modifiers. The profile includes the following five categories:

• A.

  Categorical diagnosis:

  • Specific diagnostic criteria used in clinical practice

  • Example: abdominal migraine, cyclic vomiting, functional dyspepsia

• B.

  Clinical modifiers:

  • Additional symptoms or subtypes, historical information, physical signs that subcategorize the diagnosis and affect treatment planning

  • Examples: (i) bowel predominance in IBS: diarrhea predominant, constipation predominant, or mixed; (ii) associated factors: postinfectious, sensitivity to certain foods like gluten or FODMAPs (fermentable oligo-, di-monosaccharides, and polyols)

• C.

  Personal impact of the disorder on the patients:

  • Overall effect of patient illness perceptions, behaviors, and daily functioning that influence treatment

  • Example: none, mild, moderate, or severe

• D.

  Psychosocial modifiers:

  • Psychosocial factors that influence patients’ experience of illness

  • Example: anxiety, depression, posttraumatic stress disorder, major stressors like abuse, domestic violence, drug use

• E.

  Physiological modifiers and biomarkers:

  • Physiological or biochemical parameters that may have clinical relevance or have treatment implications

  • Example: delayed gastric emptying, lactose or fructose malabsorption on breath tests

Early Learning: Developmental Aspects of Functional Gastrointestinal Disorders

To understand many of the pediatric functional disorders, it is necessary to consider the child’s point of view. For example, neonates are born with reflexes that ensure defecation. About the time that other neonatal reflexes disappear, so do the reflexes for defecation. As a consequence, the 6- to 8-week-old infant must learn to defecate by contracting the abdominal muscles to increase intraabdominal pressure, while relaxing the sphincter and pelvic floor muscles. In a few healthy infants, learning to coordinate two muscle groups simultaneously does not come easily. These infants may scream for 20 minutes or more to increase intraabdominal pressure. Finally, they relax their pelvic floors simultaneously with a Valsalva maneuver and defecate. This clinical presentation is called functional dyschezia .

The infant who perceives pain with passing a large, hard stool will learn to avoid defecation. Next, anticipation of pain with the urge to defecate results in an inability to relax the pelvic floor. This maladaptive response to fear of painful defecation, contracting of the pelvic floor with the perceived need to defecate, becomes internalized and results in functional constipation . For about the first 5 years of life, functional constipation persists unless adults ensure that the child experiences painless defecation. When asked in language that they understand, toddlers and preschool children endorse that they are afraid of hard, painful stools or ignore physical urges to defecate because of negative reactions from their social environment such as parents’ punishment for accidental incontinence or peer ridicule for smells or sounds related to defecation. School-aged children use denial to defend themselves against those who would like to help them. Their feigned nonchalance and apparent indifference occur because they are ashamed and unaware of the cause or natural history of functional constipation. They state that they do not feel the urge to defecate. Careful observation contradicts the child’s explanation for refusing to defecate. Each day the child has episodes of leg stiffening, facial expression turning blank or grimacing, and complaining of a bellyache. These episodes last about 90 seconds. These behaviors are external manifestations of the child’s perception of high-amplitude propagating colonic contractions, signaling that it is time to defecate. Unfortunately, the child with functional constipation interprets the discomfort from the stretching of the rectal wall as abdominal pain rather than an urge to defecate. At this age, educating the children and parents about functional constipation and motivating behavior change in the child are keys to successful resolution.

Functional symptoms during childhood sometimes accompany normal development (e.g., infant regurgitation), or they may arise from maladaptive behavioral responses to internal or external stimuli (e.g., in functional constipation, fecal retention is a behavioral consequence of painful defecation). The expression of an FGID depends on an individual’s autonomic, affective, and intellectual development, as well as on concomitant organic and psychological disturbances.

For example, infant regurgitation is a problem for months during the first year. Functional diarrhea affects infants and toddlers, but the outcome is unknown because stools are no longer checked after the child is toilet trained. Through the first years of life, children cannot accurately report symptoms such as nausea or pain. The infant and preschool child cannot discriminate between emotional and physical distress. With our current limitations, IBS and functional dyspepsia are diagnosed only after the child becomes a reliable reporter for pain in the early school years.

Effective Reassurance

Effective reassurance includes several components. The clinician develops a rapport with the patient and caretakers by being attentive and empathetic. Then the clinician needs to answer the four questions that concern most parents: (1) What is wrong? It is cyclic vomiting. (2) Is it dangerous? No. (3) Will it go away? Probably, but we do not know when. (4) What can we do about it? First, we educate you all about cyclic vomiting. Second, we describe the drugs we use to prevent episodes and the drugs we use to treat episodes, and weigh the risks and benefits of all the management possibilities. The third component for effective reassurance is a promise of continuing availability.

The following case vignette exemplifies how recognition of functional symptoms can help in clinical management ( Case 7.2 ).

In this case, acceptance of the benign nature of the child’s abdominal symptoms and the unwavering support of the physician enabled the mother to place an expectation on her daughter to return to school. This is a stressful juncture at which the mother feels heartless watching displays of suffering by her child on hearing that she will go to school and, on the other hand, recognition that her child’s use of genuine abdominal pain for psychological gain was leading to abnormal codependency and invalidism. Proof of the effectiveness of management was that the pain diminished within a few days and excessive school absences ceased.

When a child becomes dependent on the accepting, comforting nearness of the parent, and the parent is unable to bear the guilt created by the accusatory tantrums of her child, the parent–child relationship becomes inimical to normal development. The clinician who succeeds in managing the functional disorder complicated by anxiety-induced somatizing and helps to remove the patient’s “need to be sick” has accomplished a triumph of clinical management. It is beneficial to spend adequate time on education at the first visit. On many occasions, clinicians are pressed for time, order tests to appease a family, and defer education to later clinic visits. This approach may work to save time in the short run but leads to multiple phone calls from worried parents with each flare and unnecessary emergency room visits where further tests are ordered and invasive procedures performed. This creates a conundrum for the patient and their family, who keep receiving mixed clinical messages, and it endangers a therapeutic doctor–patient relationship as well as treatment success. Education at the first visit is a form of treatment where the clinician, by his words, creates an expectation for successful resolution of symptoms.

Biomedical Versus Biopsychosocial Models

The majority of clinicians include elements of both the biomedical and biopsychosocial models. However, it can be argued that all illnesses, organic and functional, are best managed within the framework of the biopsychosocial rather than the biomedical model of practice.

The biomedical and biopsychosocial models of practice share the same goals, namely improving patients’ well-being. However, the scope of what is considered to be impairment and the extent to which the clinician considers the origin and remedies to that impairment differ. The biomedical model limits the role of the physician to the diagnosis and treatment of disease and assumes that doing so restores well-being. The biopsychosocial model expands the meaning of the goal and the clinical process by which it is achieved. Illness is defined as the patient’s subjective sense of suffering. The goal of management is to identify the patient’s disease as well as other factors contributing to suffering.

A schematic summary by which the biomedical and biopsychosocial models can be contrasted is presented in Fig. 7.2 . The large circle represents illness . The six smaller circles within it represent six constituent categories, one or more of which may contribute to a patient’s illness. Category one represents disease . This category is the principal focus of the biomedical model. Category two represents psychological disorder ; that is, behavior or a psychological syndrome or pattern causing distress and disability. Excluded from this category are normal emotional responses to stressful events, such as grief at the loss of a loved one. The third category represents functional symptoms . The fourth category represents somatizing , symptoms that are associated with emotional distress and impairment. ^{, ,} The fifth category represents symptoms that are manifestations of normal development and are neither organic nor functional but prompt patients to seek medical evaluation (e.g., adolescent gynecomastia). The sixth circle represents failure in the relationship between the patient and society , such as no access to treatment. This scheme helps the clinician explore areas of illness that are often neglected in the biomedical model of care.

Treatment

Once the clinician is sure that the problem meets symptom-based diagnostic criteria, it is helpful to read aloud to the family the criteria from the Rome IV classification. ^, Reading from a Rome IV document is a strong argument for parents who are not convinced by the clinician’s words alone. List all the disorders if the problem meets diagnostic criteria for more than one disorder. Next, it is helpful to provide the patient with a plausible explanation for the problem. Following education, there may or may not be a need for further treatment. Effective reassurance may be all that is needed. To reinforce the educational lessons, and to assist one parent with describing the disorder to other family members, it is a good idea to hand a parent a pamphlet about the disorder obtained from the International Foundation for Functional Gastrointestinal Disorders at www.IFFGD.org .

Chronic abdominal pain is the most common chief complaint in pediatric gastroenterology clinics. Chronic pain is often caused by a sensitization of primary visceral afferent nerves to pressure and stretch (primary hyperalgesia) and amplification of pain messages in CNS nonspecific arousal systems (secondary hyperalgesia). Chronic pain is associated with alterations in physiologic and anatomic brain regions. Treatment of chronic neuropathic pain may focus on the CNS and/or afferent neurons from the hollow viscus. Pain perception occurs in the brain cortex. It is influenced by past experiences, catastrophization, and expectations for pain as well as afferent signals. Catastrophization, the belief that symptoms can only worsen and that the patient is helpless, further activates autonomic arousal. Similarly, an external locus of control, the belief that the suffering can be reduced only from outside sources, interferes with coping and amplifies arousal.

Chronic pain treatment may involve drugs and/or psychotherapy. A systematic review found limited efficacy of pharmacologic therapy in children with FGIDs. Randomized controlled trials of cognitive behavioral therapy (CBT), guided imagery, and hypnosis ^, have shown to be effective in children and adults with IBS and functional abdominal pain. A randomized, controlled trial comparing a tricyclic antidepressant to CBT in adults proved that drugs and CBT were equivalent in the short-term relief of chronic pain from IBS, and both were better than time spent on IBS education. Psychotherapy and hypnosis have the advantage of effects that last long after the treatment period compared to drug effects that last only as long as treatment continues. ^, The disadvantage of behavioral interventions is healthcare settings in which mental health professionals may not be readily available. Telephone-based, home-based audio/CD, and internet-derived therapies are being utilized to overcome this deficit. Newer interventions like exposure-based CBT, mindfulness, and acceptance and commitment therapy (ACT) have shown benefit, especially for functional symptoms associated with anxiety.

Although evidence exists about how food, infection, inflammation, permeability, and the microbiome all contribute to triggering symptoms, pain- or nausea-associated FGIDs respond better to treatments targeting the CNS than targets outside the brain. Trials of citalopram (Celexa) in children were more successful than cisapride, tegaserod, famotidine, or rifaximin for chronic abdominal pain.

Fig. 7.3 shows several classes of drugs that affect afferent nerves and/or central arousal systems. The tricyclic antidepressants have been helpful in treating many forms of chronic neuropathic pain. In addition, amitriptyline is effective in suppressing episodes of cyclic vomiting syndrome or abdominal migraine and in preventing migraine headaches. Two controlled trials yielded equivocal results with amitriptyline in children with IBS. ^, Both trials used low doses of amitriptyline—a factor that may have been the cause of the response being the same as placebo. Alternatively, an exceptional placebo response of 80% may reflect the biopsychosocial approach of the investigators, who provided effective reassurance and an expectation that the medicine would be effective. Two retrospective studies and a small prospective study found that cyproheptadine was beneficial in the treatment of FAPDs in children. Peppermint oil alone and combined with caraway oil in proprietary formulations like menthacarin has shown promising results in IBS and functional dyspepsia. Trimebutine and drotaverine have shown benefit compared with placebo in randomized clinical trials. Rifaximin was no better than placebo in children. Mirtazapine has been effective in adults with functional dyspepsia ^, and benefits patients with weight loss who have nausea, postprandial distress, and early satiety. ^, There are no randomized, controlled trials for mirtazapine, linaclotide, lubiprostone, gabapentin, pregabalin, or eluxadoline in children.

There is some role of elimination diets like a low FODMAP diet in ameliorating symptoms in children with IBS through alterations of the gut microbiome. Newer integrative treatments like neurostimulation, acupuncture, and yoga have shown benefit in the treatment of FGIDs. Percutaneous electrical nerve field stimulation (PENFS) to the outer ear significantly improved pain and global well-being after only 3 weeks of therapy in children with FGIDs in a large, randomized, sham-controlled clinical trial. Manual and electro-acupuncture have shown benefit in adults with IBS, functional dyspepsia, and functional constipation. ^, Pediatric clinical trials are limited. Acupuncture trials in Western countries did not replicate results compared to the Eastern counterparts. Hatha yoga exercises reduced pain intensity and frequency in children with FAP and IBS in a Dutch study. Similar beneficial effects of yoga were seen in adolescents with IBS. A recent randomized, controlled trial in adults has shown comparable effects of yoga to a low FODMAPs diet.

Approach to the Child or Adolescent With Pain-Associated Disability Syndrome

The term pain-associated disability syndrome (PADS) describes a downward spiral of increasing disability and pain (or other symptom, such as nausea) for which acute pain treatments do not eliminate pain or disability—the inability to engage in activities of daily life. PADS pain may be caused by tissue pathology, but it is more often associated with one or more FGIDs. The suffering seems out of proportion to objective evidence of disease. PADS is limited to preteens and teens. It is more commonly seen in adolescent females and is associated with a passive coping style and nearly always with a sleep disorder. PADS patients have overt or undiagnosed cognitive or emotional stressors that must be addressed to relieve underlying autonomic arousal. FGIDs are sometimes associated with joint hypermobility. A subset of these patients, especially teenage females, report a plethora of GI symptoms such as recurrent abdominal pain, functional nausea, bloating, and constipation. In addition, they display heterogenous clinical features like orthostatic hypotension, chronic fatigue, ^, anxiety, depression, panic attacks, migraine, sleep disturbance, autonomic nervous system dysfunction, ^, and impairment of daily functioning. Depending on which subspecialist they see, patients are diagnosed with a different disorder. A cardiologist will treat their orthostatic intolerance, that is, somatic symptoms in the upright position associated with an increase in heart rate (Postural Orthostatic Tachycardia Syndrome [POTS]) or decrease in blood pressure (orthostatic hypotension) , a neurologist their migraines and dysautonomia, and a gastroenterologist their FGIDs. We hypothesize that these patients suffer from PADS, and the underlying autonomic arousal governs most of their symptoms.

PADS patients fall into a gap between biomedical medicine and conventional mental health, as central and enteric nervous systems interact. Pain activates CNS arousal. Pain memories create an expectation for more pain; catastrophization and a maladaptive coping style are associated with patients who feel helpless to control their pain and hopeless about symptom reduction. Symptoms are inversely proportional to the patient’s perception of his or her own academic or social competence. Although brief interventions may improve symptoms, no patient stays better without the family understanding the diagnosis and participating in treatment.

If the patient and family accept the diagnosis, treatment is partially or totally successful in relieving suffering and returning the patient to normal daily activities. A multidisciplinary, biopsychosocial team approach is the mainstay of successful treatment, because clinicians, the patient, and family must communicate frequently and honestly. The burden of healing shifts from a medical model, in which the patient is passive and the clinicians test and treat, to a rehabilitation model, in which the patient is responsible for learning to help herself, with clinicians as guides. The team is usually led by a physician and a child health psychologist. Other team members may include a physical therapist, dietitian, occupational therapist or child life specialist, teacher, and family therapist.

With PADS inpatients, we have the patient and family sign a contract on the first day, promising to participate in all treatment to the best of their ability. Next, we make a schedule designed to fill every day with activities to prevent the patient from ruminating about troubles and instead exercise body and mind so there is fatigue by the end of the day, facilitating restful sleep. The physician prescribes medicine to ensure restful sleep: amitriptyline, mirtazapine, or eszopiclone. The physician may add other chronic pain medications, such as gabapentin or clonidine. The psychologist finds one or more forms of relaxation that the patient enjoys, such as relaxation breathing, yoga, hypnosis, guided imagery, or biofeedback games.

The psychologist applies CBT to introduce the patient to an active coping style and problem solving. The family asks why a psychological treatment is used to treat abdominal pain. It is helpful for them if the clinician explains that the pain is not under the patient’s control, because pain is coming from pain nerve signals that arise from pressure or stretching of the GI tract walls and are amplified by arousal centers deep in the brain. The brain modulates many body activities that are not under conscious control, such as pain, blood pressure, pulse, and respirations. However, with training, the thinking part of the brain can learn to control these. “Take respirations: please hold your breath! Now the thinking part of the brain is controlling your respirations, overriding the unconscious control. OK. Breathe again.” With CBT, catastrophic, negative thoughts are replaced by hope for successful treatment. Passive behaviors are replaced by active coping. The physical therapist provides an exercise program that is enjoyable for the patient and guaranteed for success each day, such as walking the mall or running with the family dog. The occupational therapist may work on massage to put good feelings into the brain. Music therapy, Child Life services, and homework add to a full day of activities.

If the psychologist diagnoses a comorbid psychological disorder amenable to drug therapy, such as panic disorder, anxiety disorder, depression, or attention deficit/hyperactivity disorder, there may be cause to add psychotropic medications. The team physician may prescribe psychotropic drugs and/or ask for a psychiatry consultant to assist. We explain to the patient and family that psychotropic drugs reduce suffering to help the patient focus on learning the skill set she will need to avoid a recurrence and that we plan to taper the drugs as soon as the patient acquires confidence in the necessary skills.

The PADS patient misses school for 2 months or more because of symptoms and repeated hospitalizations. Returning to school often requires that a treatment team member advise the school about PADS and the patient’s impending return. A gradual approach by breaking large tasks into several small tasks may be required. It is best to begin with just a few hours a day, for the patient’s favorite subjects. As with daily exercise, the idea is to choose incremental steps with expectations for success. PADS has not been described in adults or young children. There must be some developmental vulnerability to PADS, perhaps related to the identity uncertainty and confusion that is the developmental focus at that age.

What Should a Pediatric Gastroenterology Consultation Accomplish?

The clinician explains that the brain and the GI tract are connected. Nerve circuits run in both directions, and both brain and gut influence each other. It is not helpful to separate illness into one or the other.

Management consists of communication that satisfies the parents’ and child’s cognitive and emotional needs caused by the child’s symptoms. How can their particular needs be known? This can be accomplished by asking four open-ended questions of parents. (This might best be done in the absence of the child.)

• 1.

  What have you been told about your child’s symptoms?

• 2.

  What are your concerns now?

• 3.

  What is your worst fear?

• 4.

  What are your spouse’s concerns?

If the doctor–parent rapport is good (i.e., if the parents feel that the physician has listened to them with respect and empathy) the parent may reveal, in depth, exactly what is needed from the clinician for them to feel that the illness or symptoms are under control. This task is accomplished by conveying three essential communications . The first is an understanding of the symptoms, including (a) the diagnosis (which implies that their child’s symptoms are not unique and that the physician isn’t at a loss); (b) the mechanisms of symptom production; that is, what goes on physiologically that creates the symptom; (c) the physically benign nature of functional symptoms; (d) what to do about the symptoms when the child seems to be in severe discomfort; and (e) the outlook regarding the course of the symptoms over time; that is, will recovery take days, months, or years?

The second essential communication is effective reassurance . Information alone may not enable parents to change their focus from the child’s symptoms to the goal of pursuing normal development, such as returning to regular school. To change parents’ behavior, the clinician must try to discover the parents’ unstated and perhaps unrecognized fears. The unhurried clinician discerns clues that may seem unimportant but are deeply painful, such as a parent who lost a sibling or parent during childhood. Once these emotional burdens are uncovered, the displacement of emotional pain from the parent’s past onto the child’s current symptoms may be relieved by telling the parent that, notwithstanding the tragedy of their own parent’s colon cancer, in general, colon cancer in children is extremely rare. The moment reassurance becomes effective, it is signaled by a change in the parent’s mood from worry and frustration to perceptible relief.

The third essential communication is based on the recognition that physicians make mistakes. Diseases can be missed or new ones supervene. Therefore, the physicians’ offer of continuing availability by telephone or email is a warranty for the diagnosis, the management plan, and the doctor’s unfailing open-mindedness toward any future concern. Time becomes a diagnostic and therapeutic tool. Functional symptoms are not easily “cured” and may recur intermittently for years. Continuity of care by a physician who is willing to “own the problem” together with the parents and child is a powerful antidote to obsessive worry and overutilization of medical resources.