CHAPTER 21 Biopsychosocial Issues in Gastroenterology
CONCEPTUALIZATION OF GASTROINTESTINAL ILLNESS
BIOMEDICAL MODEL
In the practice of medicine, feeling confused, even stuck, when discrepancies exist between what we observe and what we expect is not uncommon. This experience may occur when diagnosing and caring for a patient who has symptoms that do not match our understanding of the degree of disease. In Western civilization, the traditional understanding of illness (the personal experience of ill health or bodily dysfunction, as determined by current or previous disease as well as psychosocial, family, and cultural influences) and disease (abnormalities in structure and function of organs and tissues)1 has been termed the biomedical model.2 This model adheres to two premises. The first is that any illness can be linearly reduced to a single cause (reductionism). Therefore, identifying and modifying the underlying cause is necessary and sufficient to explain the illness and ultimately lead to cure. The second is that an illness can be dichotomized to a disease, or organic disorder, which has objectively defined pathophysiology, or a functional disorder, which has no specifically identifiable pathophysiology (dualism). This dichotomy presumes to distinguish medical (organic) from psychological (functional) illness or relegates functional illness to a condition with no cause or treatment.
The limitations of this model are now becoming evident; modern research has shown a blurring of this dichotomy,3,4 as illustrated by the following case history.
This case of a patient with a severe functional GI disorder5,6 can be challenging when approached from the biomedical model. In addition to difficulties in diagnosis and management, strong feelings may occur that are maladaptive to the physician-patient relationship, for several reasons.7 First, the physician and patient approach the problem using a functional-organic dichotomy. With no evidence of a structural (organic) diagnosis to explain the symptoms for over 20 years, the patient still urges that further diagnostic studies be done to “find and fix” the problem, and the physician orders an upper endoscopy. However, failure to find a specific structural cause for medical symptoms is the rule rather than the exception in ambulatory care. In a study involving 1000 ambulatory internal medicine patients,8 only 16% of 567 new complaints (and only 11% for abdominal pain) over a three-year period were eventually found to have an organic cause, and only an additional 10% were given a psychiatric diagnosis. This patient has functional abdominal pain syndrome,9,10 one of 27 adult functional GI disorders11 that comprise over 40% of a gastroenterologist’s practice (see Chapter 11).12 Mutual acceptance of this entity as a real diagnosis is the key to beginning a proper plan of care. Because functional GI disorders do not fit into a biomedical construct (i.e., they are seen as an illness without evident disease),4 the risk that unneeded and costly diagnostic tests will be ordered to find the cause continues, as illustrated by the physician’s ordering another upper endoscopy. This approach may deflect attention away from the direction of proper management.
Second, psychosocial features are evident, including major loss, depression, abuse history, and maladaptive thinking (i.e., catastrophizing and perceived inability to manage the symptoms), in addition to the possible development of narcotic bowel syndrome (see Chapter 11), which adversely influence the clinical outcome and are amenable to proper treatment.13–15 These features are ignored or minimized, however, reflecting that patients and physicians tend to view psychosocial factors as separate from, and often less important than, medical illness.16 In reality, the psychosocial features are so relevant to the illness presentation that by addressing them the patient may improve. Ultimately, the physician, possibly recognizing that these issues are important, may feel unable to manage the problems and refers Ms. L to a psychiatrist. In turn, the psychiatrist also approaches the problem dualistically, noting the depression but also indicating uncertainty and even concern as to whether a medical diagnosis has been overlooked. These competing viewpoints may only confuse the patient.
Third, difficulties exist in the physician-patient interaction. The patient’s and physician’s goals and expectations for care are at odds. Whereas the patient wants a quick fix, the physician sees the condition as chronic and ultimately requiring psychiatric intervention, not narcotics, which could do harm.15 In response, the patient requests referral to another facility. This maladaptive interaction and poor communication relating to differing understandings of the illness and its treatment could have been avoided by addressing these differing views and mutually negotiating a plan of diagnosis and care.
This “vicious cycle” of ineffective care (Fig. 21-1) results from the limitations imposed by the biomedical model. The vicious cycle occurs not only among patients with functional GI disorders, but also among patients with organic disorders such as inflammatory bowel disease (IBD). In such cases, pain and diarrhea are not explained by the degree of disease activity, and the patient likely has irritable bowel syndrome (IBS) as well (so-called IBD-IBS; see Chapters 111, 112, and 118).3 The reality is that (1) medical disorders and patient symptoms are inadequately explained by structural abnormalities; (2) psychosocial factors predispose to the onset and perpetuation of illness and disease, are part of the illness experience, and strongly influence the clinical outcome regardless of diagnosis; and (3) successful application of this understanding and proper management require an effective physician-patient relationship.
BIOPSYCHOSOCIAL MODEL
The biopsychosocial model2,16 proposes that illness and disease result not from a single cause, but from simultaneously interacting systems at the cellular, tissue, organism, interpersonal, and environmental levels. Furthermore, psychosocial factors have direct physiologic and pathologic consequences, and vice versa. For example, change at the subcellular level (e.g., human immunodeficiency virus infection or susceptibility to IBD) has the potential to affect organ function, the person, the family, and society. Similarly, a change at the interpersonal level, such as the death of a spouse, can affect psychological status, cellular immunity, and, ultimately, disease susceptibility.17 The model also explains why the clinical expression of biological substrates (e.g., alterations in oncogenes) and associated responses to treatment vary among patients. The biopsychosocial model is consistent with emerging scientific data about the mechanisms of disease and clinical care and is assumed to be valid in this discussion.
Figure 21-2 provides the framework for understanding the mutually interacting relationship of psychosocial and biological factors in the clinical expression of illness and disease. Early life factors (e.g., genetic predisposition, early learning, cultural milieu) can influence an individual’s later psychosocial environment, physiologic functioning, and disease (pathologic) expression, as well as reciprocal interactions via the brain-gut (central nervous system [CNS]–enteric nervous system [ENS]) axis. The product of this brain-gut interaction will affect symptom experience and behavior, and ultimately the clinical outcome. Figure 21-2 will serve as a template for the outline and discussion that follows.
EARLY LIFE
EARLY LEARNING
Developmental Aspects
Certain GI disorders may be influenced by learning difficulties or emotionally conflicting or challenging interactions that occur early in life. These disorders include rumination syndrome (see Chapter 14),18 anorexia nervosa (see Chapter 8),19 functional (psychogenic) vomiting (see Chapter 14),20 and constipation (see Chapter 18), all of which can develop based on early conditioning experiences. Disorders of anorectal function (e.g., pelvic floor dyssynergia and encopresis) also may have resulted from learning difficulties relating to bowel habit21 or abuse (see Chapters 17 and 18).22 Encopretic children may withhold stool out of fear of the toilet, to struggle for control, or to receive attention from parents.23 One study has proposed that encopretic children are more likely than controls to have been toilet-trained by coercive techniques, have psychological difficulties, and have poor rapport with their mothers.24
Well-designed studies have supported the role of early modeling of symptom experience and behavior in the clinical expression of GI symptoms and disorders.14 In particular, childhood sexual and physical abuse can have physical consequences, thereby affecting the development or severity of functional GI disorders,25 and early family attention toward GI symptoms and other illnesses can influence later symptom reporting, health behaviors, and health care costs.26
Physiologic Conditioning
Early conditioning experiences may also influence physiologic functioning and possibly the development of psychophysiologic disorders. Psychophysiologic reactions involve psychologically induced alterations in the function of target organs without structural change. They often are viewed as physiologic concomitants of an affect such as anger or fear, although the person is not always aware of the affect. The persistence of an altered physiologic state or the enhanced physiologic response to psychologic stimuli is considered by some as a psychophysiologic disorder. Visceral functions such as the secretion of digestive juices and motility of the gallbladder, stomach, and intestine can be classically conditioned,27 even by family interaction. Classic conditioning, as described by Pavlov, involves linking a neutral food or unconditioned stimulus (sound of a bell) with a conditioned stimulus (food) that elicits a conditioned response (salivation). After several trials, the unconditioned stimulus is able to produce the conditioned response. By contrast, operant conditioning involves the development of a desired response through motivation and reinforcement. Playing basketball is an example; accuracy improves through practice, and the correct behavior is reinforced by the reward of scoring a basket. Consider the following case.
In this case, the parent focused on the abdominal discomfort as an illness that required absence from school rather than as a physiologic response to a distressing situation. The child then avoided the feared situation. Repetition of the feared situation not only may lead to a conditionally enhanced psychophysiologic symptom response, but also may alter the child’s perception of the symptoms as illness, thereby leading to health care–seeking behaviors later in life (illness modeling).28 For example, in two studies,27,29 patients with IBS recalled more parental attention toward their illnesses than those with IBS who did not seek health care; they stayed home from school and saw physicians more often and received more gifts and privileges. Somatic responses to stressful situations may be reduced when the parent openly solicits and responds to the thoughts and feelings of the child, thus making these thoughts and feelings acceptable.
CULTURE AND FAMILY
Social and cultural belief systems modify how a patient experiences illness and interacts with the health care system.30 The meaning that an individual attributes to symptoms may be interpreted differently, even within the same ethnic group. Qualitative ethnographic studies conducted in New York City in the mid–twentieth century among white immigrants highlighted important cultural differences in pain behaviors.31,32 In these studies, first- and second-generation Jews and Italians were observed to embellish the description of pain by reporting more symptoms in more bodily locations and with more dysfunction and greater emotional expression. As noted by one Italian patient, “When I have a headache, I feel it’s very bad and it makes me irritable, tense, and short-tempered.” By contrast, the Irish might minimize the description of the pain: “It was a throbbing more than a pain,” and the “Old Americans” (Protestants) were stoic. These behaviors related to family attitudes and mores surrounding illness either reinforce or extinguish attention-drawing symptom reporting. As a further elaboration, whereas Italians were satisfied to hear that the pain was not a serious problem, the Jewish patients needed to understand the meaning of the pain and its future consequences, with the latter possibly relating to cultural influences on the importance of the acquisition of knowledge within the culture. Geographic differences are also noted with regard to worries and concerns about having IBD—for example, Southern European patients, such as Italian and Portuguese patients, report more and greater degrees of concern than their northern European counterparts.33
These cultural influences can shape health seeking and the respective roles of physicians and patients. From a global standpoint, 70% to 90% of all self-recognized illnesses are managed outside traditional medical facilities, often with self-help groups or religious cult practitioners providing a substantial portion of the care.34 Rural cultural groups, including Mexicans living on the American border, more often will go to a community healer (e.g., a curandero) first despite access to a standard medical facility.35 When given the option, the Romani (gypsies) will select only the top physicians (ganzos) to take care of a family member.36 Among whites, one third see practitioners of unconventional treatments (e.g., homeopathy, high colonic enemas, crystal healing) at a frequency that exceeds the number of primary care visits, and most do not inform their physicians of these treatments.37 Conversely, physicians may judge the appropriateness of patient behaviors on the basis of their own cultural biases and make efforts to show them the right way without first understanding the patient’s illness schema. Considering the hot-cold theory of illness practiced by some Puerto Ricans, if a clinician prescribes a hot medicine (not related to temperature) for a hot illness, the patient might not take that medicine. From a diagnostic standpoint, health care providers in the rural south need to be familiar with root working, a form of voodoo magic practiced by some rural African Americans.38 Acknowledging and addressing the patient’s beliefs can be therapeutic for the patient.
Psychosocial factors that relate to illness can be culturally determined and affect clinical management. In China, communicating psychological distress is stigmatizing,34 so when a person is in distress, reporting physical symptoms (somatization) is more acceptable,39 whereas in Southern Europe, emotional expression is not only assumed but also is a reinforcer of family support.32 In some nonliterate societies, individuals freely describe hallucinations that are fully accepted by others in the community.31 In fact, the meaning of the hallucinations, not their presence, is the focus of interest, particularly when reported by those in a position of power. Conversely, in Western societies, in which the emphasis is on rationality and control, hallucinations are viewed as stigmatizing, a manifestation of psychosis until proved otherwise.
PSYCHOSOCIAL ENVIRONMENT
LIFE STRESS AND ABUSE
Unresolved life stress, such as the loss of a parent, an abortion, a major personal catastrophic event or its anniversary, or daily life stresses (including having a chronic illness), may influence an individual’s illness in several ways, including the following: (1) producing psychophysiologic effects (e.g., changes in motility, blood flow, body fluid secretion, or bodily sensations, thereby exacerbating symptoms); (2) increasing one’s vigilance toward symptoms; and (3) leading to maladaptive coping and greater illness behaviors and health care seeking.13,40 Despite numerous methodologic limitations in studying the relationship of such psychosocial factors to illness, disease, and their outcomes, such factors clearly can exacerbate functional GI disorders14 and symptoms of certain structural disorders, such as IBD.41 Although the scientific evidence that such factors are causative in the development of pathologic diseases is compelling, based on retrospective studies and psychoimmunologic mechanisms, this conclusion is not fully established. Nevertheless, the negative impact of stressful life events on a person’s psychological state and illness behaviors requires the physician to address them in the daily care of all patients.
A history of physical or sexual abuse strongly influences the severity of the symptoms and clinical outcome.42 When compared with patients without a history of abuse, patients with a history of abuse who are seen in a referral gastroenterology practice reported 70% more severe pain (P < 0.0001) and 40% greater psychological distress (P < 0.0001), spent over 2.5 times more days in bed in the previous three months (11.9 vs. 4.5 days, P < 0.0007), had almost twice as poor daily function (P < 0.0001), saw physicians more often (8.7 vs. 6.7 visits over six months, P < 0.03), and even underwent more surgical procedures (4.9 vs. 3.8 procedures, P < 0.04) unrelated to the GI diagnosis.43 Life stress and abuse history have physiologic and behavioral effects that amplify the severity of the condition.
Several possible mechanisms help explain the relationship between a history of abuse and poor outcome.25 These mechanisms include the following: (1) susceptibility to developing psychological conditions that increase the perception of visceral signals or its noxiousness (central hypervigilance and somatization); (2) development of psychophysiologic (e.g., autonomic, humoral, immunologic) responses that alter intestinal motor or sensory function or promote inflammation; (3) development of peripheral or central sensitization from increased motility or physical trauma (visceral hyperalgesia or allodynia); (4) an abnormal appraisal of and behavioral response to physical sensations of perceived threat (response bias); and (5) development of maladaptive coping styles that lead to increased illness behavior and health care seeking (e.g., catastrophizing). Physiologically, in patients with IBS and a history of abuse, rectal distention produces more pain reporting with greater activation of the dorsal anterior cingulate cortex44 compared with patients with IBS and no history of abuse; the pain and activation of the brain subside after treatment (see later).45
PSYCHOLOGICAL FACTORS
As shown in Figure 21-2, along with life stress and abuse, a mix of concurrent psychosocial factors can influence GI physiology and susceptibility to developing a pathologic condition and its symptomatic and behavioral expression, all of which affect the outcome. The psychological factors relate to long-standing (also called trait) features (e.g., personality and psychiatric diagnosis) and more modifiable state features (e.g., psychological distress and mood). The latter features are amenable to psychological and psychopharmacologic interventions. In addition, coping style and social support provide modulating (buffering) effects.
Personality
Are there specific personalities associated with GI disorders? During the psychoanalytically dominated era of psychosomatic medicine (1920 to 1955), certain psychological conflicts were believed to underlie development of personalities that expressed specific psychosomatic diseases (e.g., asthma, ulcerative colitis, essential hypertension, duodenal ulcer).46 In the biologically predisposed host, disease would develop when environmental stress was sufficient to activate the psychological conflict. The idea that personality features specifically relate to causation of medical disease (albeit in a biologically predisposed host), however, is too simplistic. Currently, investigators view personality and other psychological traits as enablers or modulators of illness, along with other contributing factors such as life stress, social environment, and coping.
Psychiatric Diagnosis
The co-occurrence of a psychiatric diagnosis in patients with a medical disorder (comorbidity) is common, and the psychiatric diagnosis aggravates the clinical presentation and outcome of the medical disorder. The most common psychiatric diagnoses seen among patients with chronic GI disorders are depression (including dysthymia) and anxiety (including panic attacks), and these psychiatric disorders are often amenable to psychopharmacotherapeutic or psychological treatment.14
When psychiatric disorders and personality traits adversely affect an individual’s experience and behavior to the point of interfering with interactions involving family, social peers, and physicians, these disorders and traits must be attended to. These conditions can include the following: somatization disorder, characterized by a fixed pattern of experiencing and reporting numerous physical complaints beginning early in life; factitious disorder, or possibly Munchausen’s syndrome, in which a patient surreptitiously simulates illness (e.g., ingesting laxatives, causing GI bleeding, feigning symptoms of medical illness) to obtain certain effects (e.g., to receive narcotics or operations and procedures); and borderline personality disorder, in which the individual demonstrates unstable and intense (e.g., overly dependent) interpersonal relationships, experiences marked shifts in mood, and exhibits impulsive (e.g., suicidal, self-mutilating, sexual) behaviors.47 It is important for the physician to recognize these patterns to avoid maladaptive interactions, to maintain clear boundaries of medical care (e.g., not to overdo studies based on the patient’s requests) and, when necessary, to refer the patient to a mental health professional skilled in the care of patients with these conditions.
Psychological Distress
Even for a previously healthy person, having an illness can cause psychological distress, which is understood as transient and modifiable symptoms of anxiety, depression, and other mood disturbances. Psychological distress also affects the medical disorder and its outcome; it lowers the pain threshold48 and influences health care seeking for patients with a functional bowel disturbance and those with a structural disease.14 Psychosocial difficulties may not be recognized by the patient, even if evident to the health care provider. When patients with IBS who seek health care are compared with those who do not see a physician, the former group report greater psychological difficulties but also may deny the role of these difficulties in their illnesses.49 This pattern may develop early in life. The young child, Johnny, described earlier, who was becoming conditioned to report somatic symptoms when distressed, may not recognize or communicate the association of symptoms with the stressful antecedents, because these antecedents were not acknowledged or attended to within the family. The ability to become consciously aware of one’s own feelings is believed to be a cognitive skill that goes through a developmental process similar to that which Piaget described for other cognitive functions.50 This development, however, may be suppressed in oppressive family environments.
Alexithymia (from the Greek, “absence of words for emotions”) describes patients who have chronic difficulties recognizing and verbalizing emotions. Alexithymia is believed to develop in response to early traumatic experiences such as abuse, severe childhood illness, or deprivation. Patients with alexithymia may express strong emotions, such as anger or sadness, in relation to their illnesses, but they know little about the psychological basis for these feelings and cannot link them with past experience or current illness.51 This lack of understanding limits their ability to regulate emotions, use coping strategies effectively, and adjust to their chronic condition. Their tendency to communicate emotional distress through somatic symptoms and illness behavior, rather than verbally, appears to be associated with more frequent physician visits and a poorer prognosis.52 Difficulties in awareness of one’s own emotional levels has been reported in the practice of gastroenterology in patients with functional as well as structural GI disorders.53,54
COPING AND SOCIAL SUPPORT
Coping and social support modulate (by buffering [turning down] or enabling [turning up and amplifying]) the effects of life stress, abuse, and morbid psychological factors on the illness and its outcome. Coping has been defined as “efforts, both action-oriented and intrapsychic, to manage (i.e., master, tolerate, minimize) environmental and internal demands and conflicts that tax or exceed a person’s resources.”55 In general, emotion-based coping (e.g., denial or distraction), although possibly adaptive for acute overwhelming stresses, is not effective for chronic stressors, whereas problem-based coping strategies (e.g., seeking social support or reappraising the stressor) involves efforts to change one’s response to the stressor and is more effective for chronic illness. Patients with Crohn’s disease who do not engage in emotion-based coping, such as social diversion or distraction, are less likely to relapse.56 For GI diagnoses of all types, we have found57 that a maladaptive emotional coping style, specifically catastrophizing, along with the perceived inability to decrease symptoms, led to higher pain scores, more physician visits, and poorer functioning over the subsequent one-year period. Catastrophizing is also associated with more difficult interpersonal relationships,58 predicts postoperative pain,59 and contributes to greater worry and suffering in patients with IBS.60 Therefore, efforts made through psychological treatments to improve a person’s appraisal of the stress of illness and ability to manage symptoms is likely to improve health status and outcome.14
Social support through family, religious, and community organizations and other social networks can have similar benefits in reducing the impact of stressors on physical and mental illness, thereby improving ability to cope with the illness.61 Using IBD as an example, patients who have satisfactory social support are able to reduce the psychological distress related to their conditions,62 and good social support improves health-related quality of life after surgery.63
BRAIN-GUT AXIS
The combined functioning of GI motor, GI sensory, and CNS activity is considered the brain-gut axis, and dysregulation of this system’s homeostasis explains altered GI functioning, GI symptoms, and functional GI disorders to a great extent. The brain-gut axis is a bidirectional and integrated system in which thoughts, feelings, memories, and environmental influences can lead to neurotransmitter release that affects sensory, motor, endocrine, autonomic, immune, and inflammatory function.64,65 Conversely, altered functioning or disease of the GI tract can reciprocally affect mental functioning. In effect, the brain-gut axis is the neuroanatomic and neurophysiologic substrate of the clinical application of the biopsychosocial model.
