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by Melissa Fray

A strong connection exists between the brain and the digestive tract. In fact, the connection is so strong that it can be difficult to tell where one ends and the other begins. Patients with gastrointestinal (GI) disorders often experience stress, and those with anxiety disorders frequently have digestive issues. An estimated 40 to 60 percent of those with irritable bowel syndrome (IBS) have a psychiatric disorder, such as depression or anxiety. Determining whether a patient’s symptoms are the result of a physiological problem or a psychosomatic one can be tricky for GI fellows and experienced gastroenterologists alike. It may get even trickier in the incredibly stressful COVID pandemic.

There is a long tradition of linking disorders of unknown etiology to mental health issues. Before the development of flexible endoscopy allowed gastroenterologists see inflammation and ulcers in the colon, for example, most practitioners assumed the symptoms of ulcerative colitis (UC) were the result of the patient’s unresolved emotional problems. Psychologists of yore chalked it up to Freudian anal regression, in which they attributed GI symptoms to traumas occurring during patients’ toilet training.

Through the 1970s, researchers continued to investigate the mental health issues underlying GI problems, even as other scientists were studying the efficacy of immunotherapy. A 1990 literature review of 138 studies failed to find an association between psychological factors and ulcerative colitis. The review legitimized UC as an organic disease process, but it shifted the focus away from the contributions stress and psychological have on GI disorders.

Research has come full circle in the years since, however, and has firmly established the brain-gut connection.  One recent study shows that psychological trauma and irritable bowel syndrome (IBS) are often co-morbid conditions, for example, while another study establishes a connection between mental health problems and gastrointestinal disorders.

Which Comes First – Stress or GI Problems?

Living with chronic, unpredictable and often uncomfortable digestive symptoms can have a significantly negative effect on daily life – it can also be quite stressful. GI symptoms, such pain, diarrhea, and constipation can interfere with nearly every aspect of a patient’s activities; they can also prevent the patient from engaging in meaningful activities that support physical and mental wellness. The constant and uncomfortable nature of many digestive issues causes many patients to experience a wide range of emotions, from anxiety and stress to agitation and depression.

The gut contains its own intrinsic enteric nervous system (ENS) that communicates directly with the central nervous system (CNS). In fact, there are about 100 million neurons in the small intestine alone, which means the ENS is the largest collection of neurons outside the brain. The ENS is in constant communication with the brain; stress can affect this brain-gut communication to make the CNS more sensitive to pain, bloating, and other discomfort in the gut.

The gastrointestinal tract also contains bacteria that can affect the health of the GI system, as well as influence the ability to think and feel emotions. Stress can cause changes to the gut microbiome, and fluctuations in the microbiome can in turn influence mood.

The American Psychological Association (APA) recognizes the connection between psychological stress and GI disorders. The APA also acknowledges the long-held theory that early life stress can affect nervous system development and the physiological reactions to stress in ways that can increase the risk for GI problems later in life.

Stress can change eating habits or increase the use of tobacco and alcohol to increase the risk of acid reflux, for example. Acute stress can increase the severity of heartburn pain, make swallowing difficult, or increase the amount of air swallowed while eating to cause belching, flatus, and bloating. Stress can also change the gut’s microbiome, and decrease gastric emptying while accelerating colonic transit.

When a Digestive Disorder is Not a GI Problem

When diagnosing some GI problems, gastroenterologists must sometimes look beyond the gut, especially when imaging and lab tests have ruled out the usual digestive disorders. Certain clues can help gastroenterologists identify situations in which anxiety disorders are triggering GI problems. A clinician can ask the patient about any burdensome life events, for example, or find out if the patient has recently experienced anxiety, depression, or stress.

The clinician can also look for physical signs of stress, which can include:

  • Dyspepsia
  • Constipation, diarrhea
  • Forgetfulness
  • Frequent aches and pains
  • Headaches
  • Lack of energy or focus
  • Stiff jaw or neck
  • Fatigue
  • Sexual problems
  • Hypersomnia or insomnia
  • Use of alcohol or drugs to relax
  • Changes in weight

To improve patient outcome, the gastroenterologist may refer patients with anxiety-related GI problems to a psychologist. During the consultation, the psychologist or mental health professional will assess the patient’s symptoms and assess the role stress and anxiety play in those symptoms. The psychologist will identify challenges the patient has with managing their GI and mental health symptoms. The mental health professional will also determine if counseling should be included in the patient’s treatment, and work with the gastroenterologist to create a personalized treatment plan for the patient.

A number of treatments for stress and anxiety are available. Meditation and mindfulness-based stress reduction (MBSR) is a program that helps people become more aware of how negative thoughts can affect physical symptoms. MBSR can reduce stress and anxiety, improve memory and focus, calm emotional undulations, and help patients develop greater resilience to stressors. Cognitive behavioral therapy (CBT) is a type of talk therapy that challenges and changes unhealthy cognitive distortions and behaviors to improve coping strategies. Acupuncture and massage can also help ease stress to alleviate GI symptoms.

Gastroenterologists who make the connection between anxiety disorders and gastrointestinal problems can help patients discover the underlying causes of their symptoms, and build a treatment plan to create a healthier, more comfortable life.