Biopsychosocial Issues in Gastroenterology

This chapter presents an overview of how psychosocial factors are related to GI function, disease susceptibility, clinical illness, and outcomes and provides an integrated approach to the care of the patient with GI illness.

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 common. 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) has been termed the biomedical model. This model adheres to 2 premises. The first is that any illness can be linearly reduced to a single cause (reductionism), so identifying and modifying the underlying cause is necessary and sufficient to explain the illness and ultimately lead to cure. Although this approach may seem to work for acute infectious diseases, it does not work for chronic infections such as tuberculosis and HIV infection, for which host factors also play a role in the clinical expression. Furthermore, the biomedical model is not applicable to chronic diseases such as IBD that have genetic, environmental, and psychosocial contributions to their phenotypic expression. The second premise is that an illness can be dichotomized to a disease, or organic disorder , that has objectively defined pathophysiology or a functional disorder that 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. In recent times, however, we have seen the “organification” of functional GI disorders, as well as functional components of medical diseases.

The limitations of the biomedical model are well illustrated by the following case history.

This case of a patient with a severe functional GI disorder (FGID) can be challenging when approached from the biomedical model. In addition to difficulties in diagnosis and management, strong feelings may arise that are maladaptive to the physician-patient relationship, for several reasons . First, the physician and patient approach the problem dualistically. 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. 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, only 16% of 567 new complaints (and only 11% of abdominal pain) over a 3-year period were eventually found to have an organic cause, and only an additional 10% were given a psychiatric diagnosis. This patient has centrally mediated abdominal pain syndrome , 1 of 37 adult FGIDs that comprise over 40% of a gastroenterologist’s practice (see Chapter 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, they are often considered an illness without evident disease, which increases the risk that unneeded and costly diagnostic tests will be ordered (e.g., another upper endoscopy). A study by Linedale and colleagues noted that, when comparing FGIDs to “organic” GI disorders, gastroenterologists used more qualified (uncertain, less confident) language when diagnosing patients; such lack of confidence in diagnosis often leads to unnecessary investigations and a rejection of the biopsychosocial model of illness. Also important is the likely development of narcotic bowel syndrome, which further adversely influences the clinical outcome but is amenable to proper treatment (see Chapter 12 ).

Notable psychosocial features contributing to this patient’s illness are evident—major loss, depression, an abuse history with PTSD, catastrophic thinking—yet these features are minimized. The patient views psychosocial factors as separate from, and often less important than, a specific medical disease, and the physician feels unable or unwilling to address them and refers Ms. L to a psychiatrist. In turn, the psychiatrist notes the psychological features but raises concern about whether a medical diagnosis has been overlooked. These viewpoints deflect attention from the relevant diagnoses and proper management, so the process of seeking a diagnosis continues.

A related feature in this case is impairment in the interaction between the physician and patient; their goals and expectations for care are at odds. Whereas the patient wants a quick fix, the physician sees her condition as chronic and ultimately requiring psychological intervention. In response, the patient requests referral to another facility, a response that might have been avoided if the physician had used communication skills that focused on education and negotiation of a mutual plan of care.

This “vicious cycle” of ineffective care ( Fig. 22.1 ) results from the limitations imposed by the biomedical model. The cycle occurs not only for patients with FGIDs but also for those with structural disorders such as IBD, for which pain and diarrhea are not explained by the degree of inflammation seen in laboratory values or through endoscopy. Indeed, 40% to 60% of patients with IBD exhibit IBS-type symptoms while their IBD is in remission. The reality is that (1) the patient’s symptoms are incompletely explained by structural abnormalities; (2) psychosocial factors predispose to the onset and perpetuation of illness and disease, contributing to the illness experience and strongly influencing the clinical outcome; and (3) successful application of this understanding and proper management require an effective physician-patient relationship.

Fig. 22.1, Patient–physician vicious cycle. The vicious cycle relates to 3 components: (1) functional-organic dichotomy in which the diagnosis of a functional GI disorder is not recognized, and the effort is directed toward further tests to identify an organic disease; (2) limited ability to identify and address underlying psychosocial factors that contribute to the illness; and (3) an impaired patient-physician relationship, with a lack of shared decision making about diagnosis and treatment. As indicated in this diagram, the risk of the vicious cycle is for increased testing, high health care costs, many referrals, and mutual dissatisfaction in care until the cycle is broken.

Biopsychosocial Model

The biopsychosocial model 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., HIV infection, 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. The model also explains why the clinical expression of biological substrates (e.g., alterations in oncogenes) and associated responses to treatment vary among patients.

Figure 22.2 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 via reciprocal interactions within the brain-gut (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 22.2 will serve as a template for the outline and discussion that follows.

Fig. 22.2, The biopsychosocial conceptual model. Although the figure highlights functional GI diseases ( FGIDs ), it is applicable to all digestive disorders. 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 via reciprocal interactions within the brain-gut (CNS–enteric nervous system [ ENS ]) axis. The product of this brain-gut interaction will affect symptom experience and behavior and ultimately the clinical outcome.

Early Life

Learning

Early learning in regard to GI issues involves developmental aspects and physiologic conditioning.

Developmental Aspects

At or perhaps even before birth, a person’s genetic composition and interactions with the environment begin to affect later behaviors and susceptibility to illness. The earliest interactions involve feeding and elimination. According to psychoanalytic theory, when a child’s early innate impulses (e.g., to eat or defecate) confront external environmental (i.e., parental) constraints, situations of conflict arise; normal personality development involves successful resolution of these conflicts. The complex behaviors of feeding and elimination—sources of intense gratification to the infant—must gradually be controlled by the growing child according to the prevailing mores of family and society. To varying degrees during development, these adopted constraints remain in conflict with desires for immediate gratification. With increased motor control of these functions, the child can defy or comply with environmental constraints by choosing to eat, resist eating, bite, defecate, or withhold stool. When and how these behaviors are displayed will depend on the child’s needs and the quality and intensity of the environmental influences affecting them. Behaviors learned during this period are considered pivotal to the child’s personality and later interaction with the environment, including the development of autonomy, distinguishing right from wrong, and disciplining impulses in a socially acceptable manner, not to mention bowel functioning. Conversely, failure to resolve these early conflicts may make the adult vulnerable in situations that tax these character traits.

Certain GI disorders may be influenced by learning difficulties or emotionally challenging interactions that occur early in life. Disorders of anorectal function (e.g., dyssynergic defecation, encopresis) may have resulted from painful defecation or difficulties relating to bowel training or to abuse and can be treated by reconditioning through anorectal biofeedback. Encopretic children may withhold stool out of fear of the toilet, to struggle for control, or to receive attention from parents.

Well-designed studies have supported the role of early modeling of symptom experience and behavior in the clinical expression of GI symptoms and disorders. In particular, childhood sexual and physical abuse can have physical consequences, thereby affecting the development or severity of FGIDs. Early family attention toward GI symptoms and other illnesses can influence later symptom reporting, health behaviors, and health care costs.

Physiologic Conditioning

Early conditioning experiences may also influence physiologic functioning and the development of psychophysiologic disorders. Psychophysiologic reactions involve psychologically induced alterations in the function of target organs, without structural change. They are often viewed as physiologic concomitants of emotions such as anger or fear, although the person is not always aware of these emotions. Persistence of an altered physiologic state or an enhanced physiologic response to psychological stimuli is considered a psychophysiologic disorder by some researchers. Visceral functions such as secretion of digestive juices and motility of the gallbladder, stomach, and intestine can be classically conditioned even by family interaction. Classical conditioning , as described by Pavlov, involves linking an unconditioned stimulus (sound of a bell) with a conditioned stimulus (food) that elicits a conditioned response (salivation). After several trials, the unconditioned stimulus can produce the conditioned response. It has been demonstrated that fear of benign GI sensations can be acquired through classical conditioning, a finding that has implications for newer behavioral treatments that incorporate exposure-based techniques (see later). In the first study of its kind, 52 healthy participants with no history of GI symptoms were randomized to either a condition in which a nonpainful esophageal balloon distention preceded a painful one (experimental) or to a condition in which the painful condition was administered but not paired with the benign balloon distension (control). The experimental group demonstrated higher pain expectancy, augmented skin conductance response, and a potentiated startle reflex in response to benign balloon distention but fortunately were able to be deconditioned through an extinction paradigm after the experiment was completed.

By contrast, operant conditioning involves 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. Staying home allowed the child to avoid the feared situation without addressing the determinants of the fear. Repetition of the feared situation may then lead to a conditionally enhanced psychophysiologic symptom response and may also alter the child’s perception of these symptoms as an illness, leading to health care–seeking behaviors later in life (illness modeling). Children whose mothers reinforce illness behavior have been found to experience more severe stomach aches and more school absences than other children.

In 2 studies, patients with IBS who sought health care 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. Using a validated symptom provocation test to evaluate the significance of parental solicitousness on abdominal pain complaints, parents were asked to show positive or sympathetic responses to their children’s pain complaints; when they did, the frequency of the child’s pain complaints were higher than when parents were instructed to ignore or distract the child from the same complaints.

It may be possible to remediate parental behaviors and prevent the development or exacerbation of GI complaints. In a large clinical trial of children with functional abdominal pain (now termed centrally mediated abdominal pain), 200 children and their parents were randomly assigned to cognitive-behavioral therapy (CBT) targeting the parents’ responses to their children’s pain complaints and coping strategies or to an educational control condition. Changes in parents’ cognitions about their child’s pain emerged as a mediator of positive outcomes, thereby demonstrating that a parent’s cognitions affect a child’s FGIDs.

Culture, Family, and Society

Social and cultural belief systems modify how a patient experiences illness and interacts with the health care system. This issue has become more relevant as medical education and health care systems have become global.

Illnesses in which the diagnosis is not well related to structural or physiologic disease markers are influenced by cultural factors that must be understood to be managed properly. From a global perspective, 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. Rural Mexicans living on the American border reported going to a community healer (e.g., a curandero) for GI symptoms more often than other groups, even when they had free access to a standard medical facility.

Cognitive processing of bodily feelings has a powerful cultural element, depending on how one believes the body works; some groups perceive certain symptoms to be more dangerous and threatening than do other groups. In some nonliterate societies, individuals freely describe hallucinations that are fully accepted by others in the community. 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, the emphasis is on rationality and control, and hallucinations produce fear and may be viewed as a manifestation of psychosis until proved otherwise.

The cultural difference between individuals (e.g., class structure) may influence the process of care between doctor and patient. Whereas patient-centered care is becoming the dominant model in Western cultures, in African societies, where class differences are strong, physicians and patients do not easily accept such a model. A patient might consider the physician’s efforts to involve the patient as a sign of weakness or lack of knowledge.

Cultural factors influence the ways in which symptoms are communicated. In qualitative ethnographic studies conducted in New York City in the mid-20th century, first- and second-generation Jewish and Italian patients were observed to embellish the description of pain by reporting more symptoms in more bodily locations and with more dysfunction and greater emotional expression than did other white immigrants. By contrast, the Irish tended to minimize the description of the pain, and the “Old Americans” (Protestants) were stoic. These behaviors related to family attitudes and mores surrounding illness can either reinforce or extinguish attention-drawing symptom reporting. 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, perhaps because of the importance of knowledge acquisition within the culture. In a cross-European survey of patients with IBD, Southern European patients (i.e., from Italy and Portugal) reported more and greater degrees of worry and concern about their IBD than did their northern European counterparts.

Cultural differences in explanatory models between physicians and patients may distort communication and produce misunderstandings or negative perceptions. For example, there is no word in Spanish to define the concept of “bloating,” a symptom commonly reported in English-speaking countries. In China, communicating psychological distress is stigmatizing, so when a person is in distress, reporting physical symptoms (somatization) is more acceptable. However, in Southern Europe, emotional expression is not only assumed but also reinforces the role of family support. Health care providers in the rural South of the US need to be familiar with “root working,” a form of voodoo magic practiced by some rural African Americans.

Food and diet are major determinants of symptoms that may manifest differently by culture and geographic region. They may therefore influence the intestinal microbiota, host immune function, and treatment recommendations.

Cultural influences affect the interpretation of symptoms as an illness requiring health care, to be self-treated, or to be ignored. Diarrhea is often not considered an illness requiring health care among Mexicans, because it is so common and pervasive. Margaret Mead reported that morning sickness did not exist among the pregnant women of Arapesh, among whom there is complete denial that the child exists until the time of birth.

Adherence to prescribed treatments is influenced by cultural values. When given the option, the Romani (gypsies) will select only the top physicians (ganzos) to take care of a family member and will not follow the recommendations of others. Among Puerto Ricans, type of illness is matched with the treatment based on a “hot-cold” theory. If a clinician prescribes a “hot” medicine (not related to temperature) for a “hot” illness, the patient might not take that medicine because it would disrupt the balance of humors in the body.

These types of influences indicate the importance of inquiring about the patient’s understanding of the onset, beliefs about cause, clinical course, and desired or expected treatment of an illness. They may affect adherence and possibly the response to treatment.

Psychosocial Environment

As a child moves into adulthood, genetics, culture, early learning, and other environmental influences are integrated into the individual’s unique personality and behavioral style. Life stress, the person’s current psychological state (including the presence of a psychiatric diagnosis), coping style, and degree of social support will, in combination, determine the physiologic functioning of the intestine in response to stressful stimuli, susceptibility to and activity of disease, illness perceptions and behaviors, and clinical outcome.

Life Stress and Abuse

Unresolved life stress such as 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 by (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 (called somatic or visceral anxiety ); and (3) leading to maladaptive coping and greater illness behaviors and health care seeking. Although the scientific evidence that psychosocial factors are causative in the development of pathologic diseases is compelling, current knowledge based on retrospective and correlative data is not sufficient to prove causation. 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; sometimes it is sufficient to acknowledge that life stress does not usually improve one’s health.

A history of physical or sexual abuse strongly influences symptom severity and clinical outcome, with newer research suggesting that low resilience, or the inability to recover and adapt to stressful life events (stress hyperresponsiveness), could be a potential pathway through which early life adversity increases one’s risk for IBS. Compared with patients without a history of abuse, patients seen in a referral gastroenterology practice with a history of sexual or physical abuse reported 70% more severe pain ( P < .0001) and 40% greater psychological distress ( P < .0001), spent over 2.5 times more days in bed in the previous 3 months (11.9 vs. 4.5 days; P < .0007), had almost twice as poor daily function ( P < .0001), saw physicians more often (8.7 vs. 6.7 visits over 6 months; P < .03), and even underwent more surgical procedures (4.9 vs. 3.8 procedures; P < .04) unrelated to the GI diagnosis. Therefore, life stress and abuse history have physiologic and behavioral effects that amplify the severity of the condition experienced. These effects lead to increased health care seeking and explain the higher association of abuse histories with GI illness in referral centers and specialty groups when compared with primary care.

Several possible mechanisms help explain the relationship between a history of abuse and poor outcome. These mechanisms include (1) susceptibility to developing psychological conditions that increase the perception of visceral signals or their 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 cortex (ACC) (see later), compared with patients with IBS and no history of abuse; the pain and activation of the brain subside after treatment.

Psychological Factors

As shown in Figure 22.2 , along with life stress and abuse, 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, or trait , features (e.g., personality, psychiatric diagnosis) and more modifiable, or state , features (e.g., psychological distress, mood); the latter features are amenable to psychological and psychopharmacologic interventions (see later). In addition, coping style and social support provide modulating (buffering) effects.

Personality

Personality traits (Axis II disorders) refer to enduring behaviors that are evident in early adult life and are stable throughout life. Examples of pathologic traits include borderline, obsessive-compulsive, or paranoid personality disorders; they are not amenable to specific pharmacologic or psychotherapeutic treatments.

During the psychoanalytically dominated era of psychosomatic medicine (1920 to 1955), certain psychological conflicts were believed to underlie the development of personalities that expressed specific psychosomatic diseases (e.g., asthma, UC, essential hypertension, duodenal ulcer). the idea that personality features specifically relate to causation of medical disease (albeit in a biologically predisposed host), however, is too simplistic. Investigators now view personality and other psychological traits as enablers or modulators of illness.

Psychiatric Diagnosis

Psychiatric diagnoses are definable collections of psychological symptoms and behaviors (Axis I). Gastroenterologists usually see these conditions as a factor concomitant with the presenting GI disorder. This co-occurrence of a psychiatric diagnosis in patients with a medical disorder (comorbidity) is more commonly seen in referral than primary practices, and the psychiatric diagnosis aggravates the clinical presentation and outcome of the medical disorder. Anxiety disorders are the most common psychiatric comorbidity, occurring in 30% to 50% of patients with an FGID globally. Depression is also common; depression and GI disorders overlap in about 30% of patients in primary care settings and only slightly more in tertiary settings. Suicidal ideation has been estimated to be present in 15% to 38% of patients with IBS and has been linked to hopelessness associated with symptom severity, interference with life, and inadequacy of treatment. Depression and anxiety are often amenable to psychopharmacologic or psychological treatments.

Certain psychiatric disorders and personality traits adversely affect the illness presentation to the point of interfering with family interactions, socialization, and interactions with physicians. The Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 has discarded the concept of “somatization” in favor of somatic symptom disorder (SSD; DSM5 300.82 ). In this diagnostic category, somatic symptoms may or may not be medically unexplained but are distressing, disabling, and associated with excessive and disproportionate thoughts, feelings, and behaviors for more than 6 months. Other disorders in this category include factitious disorder ( DSM5 300.19 ), which is characterized by falsification of symptoms and deceptive behaviors related to these symptoms and possibly Munchausen 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) (see Chapter 23 ). Also included is borderline personality disorder ( DSM5 301.83 ), 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. For patients with these disorders, it is important for the care provider to maintain clear boundaries of medical care (e.g., not to order studies solely based on the patient’s requests), to be clear on time constraints, and to avoid unwanted emotional interactions.

Psychological Distress

Even for a previously healthy person, having an illness can cause psychological distress, which is understood as transient and modifiable anxiety, depression, and other mood disturbances (psychological states). Psychological distress occurs in 42% to 61% of patients seen in a referral practice and has amplifying effects: it lowers one’s pain threshold, is a comorbid factor in the development of postinfection IBS and dyspepsia, and influences symptom severity, health care seeking, utilization of services, and clinical outcome. An association between psychological distress and the illness may not be evident to the patient. When patients with IBS who saw a physician were compared with those who had not seen a physician, the former group reported greater psychological difficulties but also denied the role of these difficulties in their illnesses. This pattern may develop through conditioning by the family early in life. Johnny from Case 2 , who reported somatic symptoms when distressed, may not have recognized or communicated 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 described by Piaget for other cognitive functions. This development, however, may be suppressed in oppressive family environments and appears to be associated with somatization.

Case 2

A young child, Johnny, wakes up on the day of a school examination with anxiety and “flight-fight” symptoms of tachycardia, diaphoresis, abdominal cramps, and diarrhea. The parent keeps the child home because of a “tummy-ache” and allows him to stay in bed and watch television. The teacher says that he can make up a test when he returns to school. Several days later, when the child is encouraged to go back to school, the symptoms recur.

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 comorbid 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.” Flexibility in coping strategies based on the stressor (problem-focused coping when the problem has a solution, emotion-focused coping when the problem does not have a solution) is a critical aspect of adjustment to illness. There is some evidence that patients with functional GI disorders may exhibit inflexibility in coping style, leading to negative affect and high symptom reporting. Patients with Crohn disease who score low on avoidance-based coping strategies (distraction, numbing, diversion) are least likely to relapse. For GI diagnoses of all types, a maladaptive emotional coping style, specifically catastrophizing, along with the perceived inability to decrease symptoms, is associated with higher pain scores, more physician visits, and poorer functioning over the subsequent one-year period. Catastrophizing is also associated with more difficult interpersonal relationships, predicts postoperative pain, and contributes to greater worry and suffering in patients with IBS. Efforts made through psychological treatments to improve a person’s appraisal of the stress of illness and their ability to manage symptoms is likely to improve health status and outcome.

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 the ability to cope with the illness. Negative social relationships in particular are most strongly related to poor health outcomes. Patients who perceive social support from their health care provider are also likely to see more improved symptoms and quality of life.

Brain-Gut Axis

The brain-gut axis is a neuroanatomic substrate in which the psychosocial factors just described influence the GI tract and vice versa. The “hardwiring” is a complex integrated circuitry that communicates information between the CNS and myenteric plexus to the end-organ structures. It is a bidirectional system in which thoughts, feelings, and memories lead to neurotransmitter release (the software) that affects sensory, motor, endocrine, autonomic, immune, and inflammatory function. Gut microbiota also engage in bidirectional communication with the brain via neural, endocrine, and immune pathways with significant consequences for behavioral disorders including anxiety, depression, and cognitive disorders as well as chronic visceral pain. Dysregulation of this system explains motility disturbances, pain and other GI symptoms, and FGIDs. In effect, the brain-gut axis is the neuroanatomic and neurophysiologic substrate for the clinical application of the biopsychosocial model.

Stress and GI Function

Definition of Stress

Any influence on one’s steady state that requires adjustment or adaptation can be considered stress, but the term is nonspecific and encompasses both the stimulus and its effects. The stimulus can be a biological event such as infection, a social event such as a change of residence, or even a disturbing thought. Stress can be desirable or undesirable. Some stimuli, such as pain, sex, or threat of injury, often elicit a predictable response in animals and humans. By contrast, life events have more varied effects, depending on the individual’s personal interpretation of the event. A divorce might be considered a positive experience for one person and a disappointment for another. A stimulus can produce a variety of responses in different persons or in the same person at different times. The effect may not be observed or may be a psychological response (anxiety, depression), a physiologic change (diarrhea, diaphoresis), the onset of disease (asthma, colitis), or any combination of these. A person’s interpretation of events as stressful or not and his or her response to stress depend on prior experience, attitudes, coping mechanisms, personality, culture, and biological factors, including susceptibility to disease.

Prospective studies have demonstrated that the experience of stressful life events is associated with symptom exacerbation and frequent health care seeking among adults with IBS. Chronic life stress has been reported to be the main predictor of IBS symptom intensity over 16 months even after controlling for severity of IBS, anxiety, and demographic features. Finally, stress can affect treatment outcome; one study demonstrated that the presence of a single stressor within 6 months prior to participation in an IBS treatment program was directly associated with poor outcome and higher symptom intensity at a 16-month follow-up when compared with patients who did not have such a stressor.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here