We all know that stress is bad for us. We lose sleep, energy… and even our hair over it. What we don’t think about too often is what stress does to our gut or gastrointestinal tract (GIT)!
Stress is an unavoidable condition that, at one point in time or another, affects us all. By definition stress is an acute threat to the homeostasis (or balance) of an organism (or individual). Stress can be either psychological or physical but, most importantly it causes our bodies to go into “defense mode”.
Our immune system and GIT in particular are extremely sensitive to different stressors in our lives. In your gut, stress may alter:
- secretions (digestive enzymes, stomach acid etc.)
- susceptibility to infection
- blood flow to the mucosa[2, 3, 4]
- bacteria (both good and bad). 
- the communication between your gut and your brain [6, 7]
We should worry about these alterations, because ultimately they can lead to a variety of GIT disorders. These include inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), diverticular disease, peptic ulcer disease (PUD), gastroesophageal reflux disease (GERD), as well as other functional gastrointestinal diseases, and even food allergies. [8, 9].
Gastroesophageal Reflux Disease (GERD)
In a nutshell: GERD is the most common GIT disorder related to stress, and one of the best proven ways to relieve the nasty side effects (i.e. heartburn) is to reduce stress.
Peptic Ulcer Disease (PUD)
It is well documented that stressful life events can lead to the development of stomach ulcers. This is due to an increase of the acidity of your gut. Interestingly: ulcer patients are more likely to be divorced, separated or widowed. Not only does stress contribute to PUD development, but it may also impair the GIT defenses against the damage from excess acid. 
It is worth noting two other important causes of PUD namely (1)Helicobacter pylori (Hp) infection and (2)chronic use of non-steroidal anti-inflammatory drugs. Before the discovery of Hp, however, stress was considered one of the most important risk factors for ulcer formation. 
Irritable Bowel Disease (IBD)
Exposure to stress is also a well-known risk factor for the development and exacerbation of IBD. There is evidence implicating stress in the causation or worsening of inflammation in the colon. Not all studies support this, however, so larger population-based studies are needed. Also the exact mechanism is as yet unknown, but it is probably related to one or a combination of the alterations induced by stress.
By gut flora I refer to the bacteria we all have and need in our GIT, and the bacteria we are exposed to (which we don’t necessarily want). There is evidence suggesting that stress can lead to what we call “bacterial translocation”. This, simply put, is the movement of bacteria from our gut to where we don’t necessarily want it (such as to lymph nodes, liver, spleen, kidneys or bloodstream). This movement may be important in activating the immune system, and as a result triggering inflammation in the colon. [14, 15] This effect can however be alleviated by probiotics!
Stress and Irritable Bowel Syndrome (IBS)
IBS is a common disorder with a prevalence of 10-20%, with females being 2x as likely to have IBS than males. IBS is a functional disease, the diagnosis is based primarily on the exclusion of organic disease. Typically, IBS tends to have periods where it flares up and then where it seems to go into remission. The most common symptoms of IBS include bloating, abdominal pain, diarrhoea and constipation. [16, 17]
The most important risk factors for IBS include genetic susceptibility and chronic stress. Furthermore, the key triggers include psychosocial factors, and gut exposure to infections or chronic overuse of antibiotics. 
The diagnosis of IBS is based on the Rome III criteria :
Recurrent abdominal pain or discomfort with ≥3 days per month in the last 3 months, associated with ≥2 of the following:
- Improvement of symptoms with defecation
- Onset associated with a change in stool frequency
- Onset associated with a change in stool form (appearance).
Note: You need a doctor to diagnose you with IBS based on a full assessment. You cannot diagnose yourself based solely on the Rome 9 criteria.
Some Lesser-Known Stressors
We are most aware of the emotional, relationship- and work-related stressors in life. However, there are many others. Whilst you may not necessarily see the following as stressors in your life, your body certainly does:
- lack of sufficient sleep (you need 7 – 8 hours per night)
- excess alcohol use (for women >1 drink per day, for men >2 drinks per day)
- recreational drug abuse
- poor diet
- physical injury or disease
- excessive exercise or improper exercise
- incorrect breathing (this is however a very mild stress on the body)
- chronic exposure to environmental toxins
- being overweight or obese
Whilst not all of these will elicit GIT alterations on their own, they may do so when experienced in combinations.
Although this should be fairly clear, stress is bad for your gut health. GERD, IBD, IBS, and PUD are awful acronyms for awful conditions. Try to alleviate stress in your life as much as possible, including the lesser-known stressors mentioned above.
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