Biopsychosocial Aspects of Functional GI Disorders
“It’s all in your head!”, “There’s nothing wrong with you.”, “All tests are negative.”…these phrases may be familiar to those with irritable bowel syndrome (IBS) or functional dyspepsia (FD). Yet these individuals – with functional gastrointestinal disorders – are suffering from very real, frustrating, and sometimes debilitating symptoms. For those with IBS, these symptoms include abdominal pain, gas, bloating, constipation, and/or diarrhea, while FD patients may experience pain, fullness, bloating, inability to finish meals, heartburn, a sour taste in their mouth, excessive burping, nausea, and sometimes vomiting. In fact, a 1996 British study revealed that, despite admitting to a poor knowledge of IBS, 90% of nurses believed this illness was, “all in the patient’s mind.”1 More recently, a 2003 study found that family practitioners had negative perceptions of IBS patients that could affect their care delivery.2
We now know, unequivocally, that functional gastrointestinal disorders (FGIDs), such as IBS and FD, are bona fide illnesses, affecting a large proportion of the population, many of whom never seek medical care for their symptoms. Clear and defined symptom measures, produced by well-recognized national and international medical bodies, exist to diagnose both IBS and FD. These healthcare clinicians also developed appropriate treatment regimes and support their work with a body of medical literature to aid in managing these disorders.
Still, we should not overlook the mind-body connection. Numerous studies provide evidence for the link between stressful life events or chronic stress and symptom intensity. Some physicians believe that a biopsychosocial model of illness is useful in understanding functional gastrointestinal disorders as complex conditions involving intricate interplay between biological, psychological, and social components.
Organic or Functional?
An organic disease is one in which there is a structural change to some tissue or organ of the body, whereas, a functional disorder is one in which symptoms exist without a detectable physical or physiological cause, and for which there is no diagnostic testing available. By default, some attribute a psychological or psychiatric origin to a functional symptom.
The Brain-Gut Connection
While the pathophysiology, of irritable bowel syndrome is not fully understood, researchers believe one important clue lies in the relationship between the central nervous system and the enteric nervous system, (the system controlling the gastrointestinal tract) known as the brain-gut axis. Imagine this as a busy two-way street: in one direction, the central nervous system sends signals to the digestive system telling it when to activate movement, while in the other direction, the intestines transmit messages back to the brain, which then creates sensations of fullness, hunger, discomfort, or pain. These two ‘control centres’ use the chemical serotonin as an important neurotransmitter and signaller.3 In the gut, which holds 95% of the body’s serotonin, it also gives important signals that trigger peristaltic and secretory action. Researchers postulate that in patients with IBS, these pathways have abnormal function or activity linked to serotonin levels4 and, perhaps because the brain and the gut are so highly integrated, non-biological factors play an important role in their etiology.
Biopsychosocial Model
The biopsychosocial model (BPS) for looking at illness holds that many components interact to produce disease. Its main tenets were developed and advanced by George Engel in 1977 in response to what he perceived as a need for physicians to treat all possible dimensions of illness; biological, psychological, and social. At the time Engel put forward his ideas, the dominant view of disease looked solely at biological factors in the etiology of illness (some call this the biomedical model). Engel believed that only by taking a broad view could the medical profession properly understand the origins, expression, course, and outcome of disease.
One criticism of this model is that it lacks specificity. Medical researchers want to know how different factors contribute to certain health outcomes; however, in the BPS model, each of these various elements may play a large or small part or even have no role at all, for any particular individual or any particular disorder. This ‘gray’ area leaves patients exposed to having physical symptoms blamed on psychological factors – a vulnerability easily exploited by medical insurers. Another shortcoming of the BPS model is that physicians have found it challenging to put into practice. Identifying the many dimensions at work in each individual patient may be an improbable task without a clear framework to incorporate into day-to-day practice.5,6,7
Pathophysiology is the study of the disturbance of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from a disease or abnormal syndrome or condition that may not qualify to be called a disease.
Research Sheds Some Light
Research has uncovered some factors associated with the expression of IBS. Several of these established links include a major stressful life event, chronic stress, a reported history of physical, sexual, or emotional abuse, low birth weight, and environmental triggers such as infection with bacterial gastroenteritis. In some cases, IBS symptom intensity relates to the severity of the specific associated factor. To address some of these factors, and attempt to treat the associated IBS symptoms, a number of studies have examined various psychotherapy treatments, with mixed results.8 These approaches include relaxation training, dynamic psychotherapy, hypnotherapy, and combined psychotherapies. One thorough review published in 2003, showed psychological treatment may be effective for IBS, yet could not identify any one specific therapy to work any better than the others.9
Two recent notable studies with large sample sizes and rigorous methodology demonstrated encouraging results. The first compared cognitive behavioural therapy (CBT) to patient education sessions. While pain scores did not differ significantly between groups, CBT was superior in terms of satisfaction with treatment and global well-being.10 The second study compared a pharmaceutical treatment, psychotherapy, and a control group receiving standard IBS treatment, showing significant improvement in health-related quality of life one year after treatment started for the study groups, although abdominal pain scores did not improve.11 Both of these studies found that psychological therapy was less effective for IBS patients who also had coexisting depression disorders.
Successful treatment for IBS and FD comes in many forms, addressing all dimensions of disease. Some pharmacological approaches target the serotonin levels and pathways, while others produce an analgesic effect or work on biological mechanisms.
Going Forward
When your physician asks you about your family or work life, while assessing your GI symptoms, don’t assume he or she is implying that your symptoms are imagined. Finding out about your psychological state may uncover some psychosocial stresses that, when treated, could ease your IBS experience. Whether physical symptoms actually decrease with psychological therapies is unclear, yet management skills and quality of life do improve, possibly leading to less missed work and fewer doctor visits, positive outcomes well-worth exploring.