Stress and anxiety can take a toll on the digestive system. When you are anxious, hormones and signals from the brain enter the digestive tract, and interfere with digestion. These imbalances can cause a number of gastrointestinal (GI) symptoms, including diarrhea.
Anxiety causes activation of the ‘fight or flight’ response – which can be a good thing, prompting us to take extra precautions. However, when these feelings persist in when there is no threat, they may take a toll on our physical health and cause diarrhea. Understanding this link may help you avoid symptoms and feel well again.
Diarrhea is the passing of loose and watery stools more than 3 times in a day. There are a number of of causes of diarrhea, including:
• Inflammatory bowel diseases – ulcerative colitis and Crohn’s disease
• Overactive thyroid (hyperthyroidism)
• Poor absorption of certain nutrients (malabsorption)
• Bacterial infection
• Some cancers (1)
If you have diarrhea, consulting a doctor to rule out these causes. Once these have been ruled out, the stress or anxiety may be the culprit.
Diarrhea with anxiety
Anxiety is the body’s response to an unpredictable threat and produces both cognitive and physical changes. It is believed to arise from the amygdala, a brain region that deals with intense emotions such as anger, fear, and sadness. (2)
Anxiety prepares us to confront a crisis by putting the body on alert, and nerve signals from the brain travel through the body in this response. This causes blood flow to be diverted away from the abdominal organs and unfortunately, may cause nausea and diarrhea. (3)
By voiding the bowels in diarrhea, the body prepares for survival. The digestive system suspends to provide more blood flow to parts of the body such as the skeletal muscles and although useful in ancient times, is an unnecessary response in today’s modern world.
If you also experience abdominal pain with diarrhea, it might also be irritable bowel syndrome (IBS).
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is a gastrointestinal disorder. It is ‘functional’ meaning it is not life-threatening and has no underlying physical disease, and is essentially a disorder of the gut-brain connection. It is very commonly seen in those with anxiety disorder and depression. However, this is not to underestimate the symptoms of IBS, which may be very real and distressing and include:
• Diarrhea or constipation
• Abdominal pain, often relieved with passing a bowel motion or wind
• Abdominal bloating
• Cramping (4)
IBS is extremely common, affecting 1 in 7 individuals globally and is more common women. The cause of IBS is not known, but environmental factors such as emotional stress and change of routine may trigger an attack. Anxiety is strongly associated with IBS – both onset and worsening of symptoms. (4,5)
Diagnosis of IBS
IBS is diagnosed by the ROME-IV criteria:
Recurrent abdominal pain at least 1 day per week in the last 3 months that is associated with two or more of the following:
• Related to defecation.
• Associated with a change in frequency of stool.
• Associated with a change in form (appearance) of stool. (6)
A doctor will be able to confirm a diagnosis. It is worth noting that diarrhea and anxiety can occur together in the absence of IBS.
Types of IBS
Irritable bowel syndrome can be divided into three categories, depending on whether diarrhea or constipation predominate:
• Diarrhea-predominant IBS (IBS-D): this person experiences diarrhea, first thing in the morning or after eating.
• Constipation-predominant IBS (IBS-C): this person experiences constipation, and abdominal pain and cramping are commonly triggered by eating.
• Mixed IBS (IBS-M): this person experiences alternating periods of diarrhea and constipation. (7)
If you experience diarrhea with anxiety, you may have diarrhea-predominant IBS (IBS-D), the most common form of IBS. (8)
Is diarrhea common with anxiety?
Diarrhea and other digestive complaints commonly occur with anxiety. Those with anxiety are over twice as likely to suffer from diarrhea as the general population. Further, up to 54% of those with irritable bowel syndrome (IBS) have generalized anxiety disorder. (9,10)
The ‘gut-brain connection’ helps to explain how problems with the mind and brain can affect the digestive system to account for this overlap.
The gut-brain link
Whether or not you have IBS, anxiety disorders are linked with diarrhea by the ‘gut-brain axis’. This is the two-way connection between brain and bowels that involves nerves, hormones, and gut bacteria, and a key component of the gut-brain axis is the enteric nervous system (ENS).
The ENS is often referred to as the ‘second brain’ due to its complexity and consists of millions of neurons that surround the digestive tract and control digestion. The ENS connects to the central nervous system, the brain, and spinal cord, and is literally affected by processes in your brain. (11, 12)
When diarrhea occurs with anxiety or in IBS, the ENS is malfunctioning. There is a disruption to signals controlling motility – the speed of transit of material through the intestines – that may lead to an urgent need to defecate. Hence anxiety may lead to physical digestive symptoms such as diarrhea.
What to do
If you suffer anxiety and diarrhea, you should seek immediate medical help if you experience any of the following:
• Blood in stools
• Rectal bleeding
• Fever lasting 3 days or more
• Severe abdominal pain
• Rapid weight loss
• Bowel movements do not relieve pain
If you do not suffer the above symptoms, treatments for diarrhea and stress-management strategies may improve symptoms. You may still wish to consult your doctor to confirm which treatment is right for you.
Treatments for diarrhea
Treatments for diarrhea predominantly involve rehydrating the body. These include:
• Rehydration. This is important to counteract the dehydration in diarrhea.
• Oral rehydration. To replace lost salts and minerals from diarrhea.
• Medications. Such as antibiotics if the cause is an infection or anti-diarrheal medications.
• Avoiding exercise. As strenuous exercise may further contribute to dehydration.
• Treating disease. If there is a physical basis, such as inflammatory bowel disease.
• Fluid IV replacement. In severe cases to rehydrate the body. (13)
These will ensure your body can recover from periods of dehydration associated with diarrhea. You should consult your doctor to confirm the best treatment for your condition.
As well as diarrhea treatments, stress management strategies may target the anxiety, which may be at the root cause of symptoms. Stress management techniques prevent the body from easily being triggered by outside stressors. These include:
• Hypnotherapy. The patient first undergoes hypnotic induction, then suggestions are made to address the patterns of thought associated with anxiety. This form of therapy has been shown at least as effective as CBT for treating anxiety disorders, and IBS. (14) It's possible to try hypnotherapy through a mobile app like Nerva or with your local hypnotherapist.
• Cognitive-Behavioural Therapy (CBT). This therapy involves a cognitive aspect in helping patients identify thoughts that generate anxiety and a behavioral part teaching them to respond differently to anxiety-provoking situations. These techniques help to lessen anxiety and improve gastrointestinal symptoms. (15)
• Mindfulness meditation. This practice of focusing awareness on the present moment has been shown to reduce anxiety and stress scores. IBS symptoms such as abdominal pain and bloating may particularly benefit. (16)
• Yoga. Has been shown to relieve stress and also specific symptoms of IBS that is diarrhea-predominant. Research has shown yoga more effective than anti-diarrheal medication in relieving symptoms. (17)
Over a longer period, lifestyle adjustments that may prevent symptoms of diarrhea and include:
• Staying hydrated
• Avoiding alcohol and tobacco
• Getting regular exercise
• Eating a balanced diet includes fiber, such as whole grains, lean proteins, and vegetables.
• Prioritizing sleep
• Taking probiotics (18)
What has science shown recently?
Science has recently illuminated some fascinating links between the brain and the gut. These insights are helping us to understand the connection between diarrhea and anxiety.
• Anxiety increases the speed of transit of food through the gut. One study showed that generalized anxiety disorder (GAD) causes physical changes to the digestive system. The transit of food from the mouth to rectum was found to be 14 hours, on average, in anxiety patients – much faster than the 42 hour-average in controls. Anxiety was therefore shown to physically alter speed of transit through the intestines, explaining the link between diarrhea and anxiety. (19)
• Hypnotherapy over Skype reduces symptoms of IBS. Researchers showed that symptoms of IBS improved in 65% of subjects who received hypnotherapy delivered online over Skype, compared to 76% with face-to-face treatment. Although slightly lower, the significant rate of Skype hypnotherapy means access to this form of IBS treatment could be greatly expanded. (20)
A Word from Mindset Health
The nervous system and stomach issues are intimately linked. If you experience diarrhea or other IBS symptoms and mental health conditions such as anxiety disorder, there are treatments available to help you manage stressful situations and improve your anxious stomach. Relaxation techniques and cognitive behavioral therapy may help to improve GI symptoms and improve your upset stomach, with hypnotherapy through apps like Nerva being especially helpful.