Functional Gastrointestinal Illness

Functional illness may manifest with upper and/or lower gastrointestinal (GI) symptoms. (See also Irritable Bowel Syndrome Irritable Bowel Syndrome (IBS) Irritable bowel syndrome is characterized by recurrent abdominal discomfort or pain with at least two of the following characteristics: relation to defecation, association with a change in frequency... read more and see the American College of Gastroenterology's monograph on management of irritable bowel syndrome.)

Functional GI disorders are disorders of the gut-brain interaction. Some evidence suggests that such patients have visceral hypersensitivity, a disturbance of nociception in which they experience discomfort caused by sensations (eg, luminal distention, peristalsis) that other people do not find distressing. Functional disorders are classified by symptoms related to a combination of not only visceral hypersensitivity but also motility disturbance, altered microbiota, mucosal and immune function, and central nervous system processing (1 General references Often, no objectively measurable structural or physiologic abnormality for gastrointestinal complaints is found, even after extensive evaluation. Such patients are said to have functional illness... read more ).

In some patients, psychologic conditions such as anxiety Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more (with or without aerophagia), conversion disorder Functional Neurological Symptom Disorder Functional neurological symptom disorder, previously known as conversion disorder, consists of neurologic symptoms or deficits that develop unconsciously and nonvolitionally and usually involve... read more , somatic symptom disorder Somatic Symptom Disorder Somatic symptom disorder is characterized by multiple persistent physical complaints that are associated with excessive and maladaptive thoughts, feelings, and behaviors related to those symptoms... read more , or illness anxiety disorder Illness Anxiety Disorder Illness anxiety disorder is preoccupation with and fear of having or acquiring a serious disorder. Diagnosis is confirmed when fears and symptoms (if any) persist for ≥ 6 months despite reassurance... read more (previously called hypochondriasis) are associated with GI symptoms. Psychologic theories hold that some functional symptoms may satisfy certain psychologic needs. For example, some patients with chronic illness derive secondary benefits from being sick. For such patients, successful treatment of symptoms may lead to development of other symptoms.

Many referring physicians and GI specialists find functional GI complaints difficult to understand and treat, and uncertainty may lead to frustration and judgmental attitudes. An effective physician–patient interaction reduces health care–seeking behavior by the patient. Physicians should acknowledge the patient's symptoms and provide empathy. Physicians should avoid ordering repeated studies or multiple drug trials for insistent patients with inexplicable complaints because this may promote symptom anxiety and health care–seeking behavior (2 General references Often, no objectively measurable structural or physiologic abnormality for gastrointestinal complaints is found, even after extensive evaluation. Such patients are said to have functional illness... read more ). When symptoms are not suggestive of serious illness, the physician should wait rather than embark on another diagnostic or therapeutic plan. In time, new information may direct evaluation and management. Functional complaints are sometimes present in patients with physiologic disease (eg, peptic ulcer Peptic Ulcer Disease A peptic ulcer is an erosion in a segment of the gastrointestinal mucosa, typically in the stomach (gastric ulcer) or the first few centimeters of the duodenum (duodenal ulcer), that penetrates... read more , esophagitis); such symptoms may not remit even when a physiologic illness is addressed. In some patients, testing (eg, CT) may identify incidental abnormalities that are unrelated to the symptoms.

(See also Evaluation of the Gastrointestinal Patient Evaluation of the Gastrointestinal Patient Gastrointestinal (GI) symptoms and disorders are quite common. History and physical examination are often adequate to make a disposition in patients with minor complaints; in other cases, testing... read more .)