Stress and IBS: The Gut-Brain Link, Causes, & Management

What is stress?

Before we can understand the relationship between stress and IBS, it's important to understand how stress affects your body and what causes stress.

Stress is your body’s response to difficult situations that require immediate action or adjustment. Stress may trigger the ‘fight or flight’ response as the body prepares to fight or escape from a perceived threat. This is accompanied by increase in heart rate, release of hormones such as cortisol, reduced blood flow to certain organs and slower digestion.

Types of stress include:

• ‍Eustress: This is a positive form of stress. It is usually experienced as feelings of excitement and energy.
• ‍Acute stress: A short-term stress that may be positive or negative.
• ‍Chronic stress: Long-term stress that may seem never-ending.

Normally, once the threat is gone, your relaxation response returns your body to normal. But when we experience chronic stress, this relaxation response does not occur. This is harmful as it may deplete and tax the body and lead to conditions including IBS.

Stress and IBS – Whats the link?

The gut and brain influence one another continually. In prehistoric times, this served us well: stressful situations would activate the ‘fight or flight’ system – blood flow to the stomach would reduce and the bowels empty or tense up. This would allow for more energy to flee or fight.

In today’s world, life-threatening situations are rare but we are still wired the same way. Modern ‘predators’ may come in the form of deadlines, and busy schedules and may cause ongoing stress. This chronic stress is what often leads to gastrointestinal issues such as IBS.

What evidence links stress and IBS?

The link between stress and IBS is well supported by the science.

One study, that documented people's levels of stress and IBS symptoms over 16 months, showed that chronic stress predicts the severity of IBS symptoms. During the study, almost all changes in IBS symptoms were based on changes in stress and not one patient with ongoing stress improved in IBS symptoms significantly.

Another study showed people with IBS are more sensitive to pain during stress. When placing their hands in cold water, or listening to unpleasant music, IBS patients became more sensitive to rectal sensations. This form of sensitivity to pain in the internal organs is called ‘visceral hypersensitivity’ and is associated with abdominal discomfort in IBS.

How does stress contribute to IBS?

Stress causes many changes in the body, to hormones, nerves, and levels of bacteria in the gut. These changes may lead to IBS and include:  

• Pain perception: Stress causes higher sensitivity to pain in the colon and rectum, in response to stretching. This leads to abdominal pain in IBS.
• Brain activation: Brain areas associated with attention are changed in stress, leading to a greater conscious focus on sensations in the body, and more pain.
• Gut bacteria: Levels change in response to chronic stress, potentially causing IBS as gut bacteria interact with the nervous system and immune system.
• Immune system: Becomes activated. Although this may seem like a good thing, it has adverse effects as is the case in an allergic reaction. In particular, the activation of ‘silent’ pain receptor cells increases sensitivity to pain in IBS.
• Hormonal changes: Include the release of a corticotropin-releasing factor (CRF). This leads to changes in gut bacteria, and the immune system – both of which contribute to IBS.

The gut-brain connection

These changes are features of the ‘gut-brain connection’⸺the two-way link between brain and bowels. This link is made up of several parts, including the vagus nerve and millions of neurons that surround the gut.

The neurons in the gut are complex and described as the ‘second brain’. This second brain interacts with the actual brain in a number of ways. The brain sends signals to the stomach and intestines to control digestion. Meanwhile the gut sends feedback signals back to the brain. These are usually unconscious, but in IBS become disrupted and may be felt consciously as pain.

The gut-brain connection is at the heart of IBS. At its simplest, the pain you experience through IBS, as well as other symptoms such as diarrhoea and constipation, occur because of a miscommunication between the gut and the brain.

Trauma and IBS

Just as stress can play a role in IBS, so can trauma. Up to 50% of people with IBS have experienced trauma, including PTSD, from life events such as:

• Sexual abuse
• Death of a loved one
• Emotional abuse
• Break-up of a serious relationship.

This kind of trauma is known as ‘psychosocial stress’ and is strongly linked with the development of IBS, which may be why many of the most effective treatments for IBS reduce stress and anxiety.

Stress management for IBS

IBS is a stress-sensitive condition. Several stress management strategies have been shown effective for relieving symptoms of IBS:

Yoga
‍A 2006 study showed that yoga reduced symptoms of IBS. The program consisted of a one-hour live demonstration, and an instructional video followed daily for four weeks. All measures of IBS symptoms were reduced yoga group, compared to controls on a waiting list.

Cognitive behavioral therapy (CBT)
‍Several studies show CBT improves symptoms of IBS.

Mindfulness training
‍A 2011 trial showed training in mindfulness reduced bowel-related symptoms and distress. The program emphasized the mind-body connection and present moment awareness. The program lasted eight weeks and substantial results were maintained 3-months after treatment.

Gut-directed hypnotherapy
‍Hypnotherapy targeted to the gut has been shown to reduced symptoms such as pain, bloating and wind to the same extent as the low FODMAP diet.  Imagery was used such as suggestions of the gut as a series of watery pipes, after patients were hypnotically induced. Impressively, the improvements were maintained for at least six months, and, as an added bonus, levels of anxiety were also reduced.

While IBS is not 'all in the mind', the gut-brain connection means targeting the mind through stress management can positively influence perceptions of pain in the gut. Symptoms of stress and anxiety, which worsen IBS, may also improve.

Lifestyle factors for stress management

On a day-to-day basis, positive lifestyle adjustments can also reduce chronic stress. This may in turn benefit symptoms of IBS. Important lifestyle factors to consider include:

Exercise
Exercise releases chemicals in the brain called endorphins, the body’s ‘natural painkillers’ that reduce stress and improve sleep. Even ten minutes of aerobic exercise can stimulate anti-anxiety effects.

‍Meditation
Meditation has a range of benefits to mind and body, including stress relief. An 8-week program improved overall psychological wellbeing and perceived control over life. Meditation can be easy to learn and even 5 minutes of practice can help reduce stress.

‍Maintaining a healthy diet
‍Eating whole foods and five serves of vegetables can boost mood and reduce stress. Foods high in fibre, such as wholegrain breads and cereals may lower stress, and citrus fruits and other vitamin C-containing foods reduce anxiety.

Maintaining a sense of humour
‍While this may feel challenging in times of pain and stress, laughter releases endorphins and other healthy hormones and distracts people from anger, stress and other negative emotions.

Building supportive relationships
‍A social support network helps to improve self-esteem and autonomy, reducing stress levels. Feeling supported helps to avoid loneliness, which is associated with depression and anxiety.

The Wrap Up

There is a direct connection between stress and IBS. Higher levels of stress are common among people experiencing IBS symptoms. This occurs through the gut-brain connection. Stress, anxiety and trauma  are often linked with and activate the 'fight or flight' response. This, in turn, may and effects on the digestive tract and lead to functional gastrointestinal disorders related to the cause of IBS.

To reduce psychological stress, try stress reduction strategies such as hypnotherapy or cognitive behavioural therapy. The treatment of irritable bowel syndrome is complex, but relaxation techniques may help to restore the digestive system.