Gut, brain and sleep
Anxiety and stomach problems: why stress upsets the gut
Anxiety and stress cause real physical symptoms in the gut: a churning stomach, nausea, cramps, loose stools, bloating or a loss of appetite. This happens because the brain and the gut are joined by nerves and stress hormones, which change how fast the gut moves and how sensitive it is. The symptoms are not imagined, and they usually settle when the stress passes. When they last for weeks, or come with warning signs such as bleeding or weight loss, they need a medical check, because anxiety and a gut disease can exist together.
In short
- Stress slows the stomach and speeds up the colon. That is why nausea and loose stools can come together.
- An anxious nervous system makes the gut more sensitive, so normal sensations are felt as pain.
- The link runs both ways: long-standing gut symptoms also cause anxiety.
- Bleeding, weight loss, night-time symptoms or difficulty swallowing are not explained by anxiety.
What does anxiety do to the gut?
From the brain to the gut. Stress slows the stomach and speeds up the colon. An anxious nervous system also makes the gut more sensitive, so normal sensations are felt as pain.
The stomach slows
Food stays in the stomach longer. You feel full, nauseated or unable to eat.
The colon speeds up
The result is cramps, urgency and loose stools, often just before a stressful event.
The gut becomes more sensitive
Nerves in the gut wall signal discomfort at lower levels of stretch and gas.
Heartburn feels worse
Stress heightens the sensation of reflux, even when the amount of acid is unchanged.
Appetite changes
Some people stop eating. Others eat more, and more often.
Breathing changes
Fast, shallow breathing leads to swallowed air, belching and bloating.
Which gut symptoms can anxiety cause?
- A churning or “knotted” stomach
- Nausea, often in the morning
- Loss of appetite
- Cramping abdominal pain
- Urgent, loose stools at times of stress
- Bloating and belching
- A feeling of a lump in the throat
- A dry mouth
Is it anxiety, or a gut disease?
Points to stress
- Symptoms come with stressful events and ease on rest days
- Sleep is not disturbed by the gut
- Weight is steady
- Symptoms vary from day to day
- A long history of similar episodes
Needs a medical check
- Blood in the stool, or black stools
- Symptoms that wake you from sleep
- Weight loss you cannot explain
- Symptoms that worsen steadily
- New symptoms after the age of 50
The two can exist together. Irritable bowel syndrome and functional dyspepsia are common in people with anxiety, and they are treatable in their own right. See gut-brain axis disorders.
What helps an anxious stomach?
Slow your breathing
Breathe in for about four seconds and out for about six, for five to ten minutes. This activates the calming branch of the nervous system. See ways to stimulate the vagus nerve.
Eat small, regular meals
An empty stomach and a very full one both make symptoms worse. Keep caffeine and alcohol low.
Move
A daily walk helps the bowel and the mind. In a randomised trial, regular physical activity improved IBS symptoms.
Protect your sleep
Short nights make the gut more sensitive the next day.
Understand the link
Knowing that the symptoms come from a real connection, and are not a sign of hidden disease, reduces the fear that keeps them going.
Psychological therapy
Cognitive behavioural therapy treats anxiety, and versions designed for the gut reduce IBS symptoms. See gut-directed hypnotherapy and CBT.
Medicines where needed
For the gut symptom, for anxiety, or a low-dose medicine that calms gut nerves. These are prescribed after an assessment.
Try the first step now
Breathe in as the circle grows, for about four seconds. Breathe out as it shrinks, for about six. Five to ten minutes is the usual practice.
A guided practice to follow along with. Skip the pauses if holding your breath is uncomfortable.
When should I see a doctor?
See a doctor promptly if you have
- Blood in the stool, black stools or vomiting of blood
- Weight loss you cannot explain
- Difficulty swallowing, or vomiting that will not stop
- Symptoms that wake you from sleep
- Chest pain, breathlessness or sweating. These need assessment at once and should not be put down to anxiety or gas.
See a doctor, too, if anxiety has lasted more than two weeks or is affecting your work, sleep or relationships. Tele-MANAS, the Government of India’s free mental health helpline, is available on 14416.
Questions patients ask me
Can anxiety cause stomach pain every day?
Yes. Long-standing anxiety keeps the gut’s nerves sensitive, and daily pain or discomfort can follow. Daily pain still deserves one proper assessment to rule out other causes.
Why do I get loose motions when I am nervous?
Stress hormones speed up the colon. The bowel empties sooner and the stool is looser. It is a normal response that is stronger in some people.
Can stress cause gastritis or an ulcer?
Everyday stress does not cause ulcers. H. pylori infection and painkillers do. Stress can worsen indigestion, and severe physical illness can injure the stomach lining. See gastritis.
How do I calm an anxious stomach?
Slow breathing for a few minutes, sips of water, a short walk and a small, plain meal help most people. If episodes are frequent, look at sleep, caffeine and the source of the stress.
Will treating my anxiety improve my gut symptoms?
Often, yes. The opposite is true as well: treating the gut condition reduces anxiety.
Sources
This page is written for patients and is based on the guidelines and studies below. It is for education and does not replace a consultation.
- Review of the microbiota-gut-brain axis. Cryan JF et al. Physiol Rev. 2019. PubMed 31460832
- Review of the vagus nerve in the microbiota-gut-brain axis. Bonaz B et al. Front Neurosci. 2018. PubMed 29467611
- Twelve-year study showing the brain-gut pathway runs in both directions. Koloski NA et al. Gut. 2012. PubMed 22234979
- Meta-analysis of anxiety and depression in irritable bowel syndrome. Zamani M et al. Aliment Pharmacol Ther. 2019. PubMed 31157418
- Rome IV overview of disorders of gut-brain interaction. Drossman DA. Gastroenterology. 2016. PubMed 27144617
- Network meta-analysis of psychological therapies for irritable bowel syndrome. Black CJ et al. Gut. 2020. PubMed 32276950
- Trial of physical activity for irritable bowel syndrome. Johannesson E et al. Am J Gastroenterol. 2011. PubMed 21206488