IBS

IBS Triggers: Diet, Hormones, and Stress

Certain foods, hormonal fluctuations, and stress can worsen the symptoms of irritable bowel syndrome. Learn more about which factors may be affecting your digestive system.

Quinn Phillips
By Medically Reviewed by 
Reviewed:
Medically Reviewed
young woman stomach pain sitting on bed with dog

Research shows that stress can worsen IBS symptoms.

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When you have irritable bowel syndrome (IBS), a number of factors can cause symptoms stemming from your large intestine, like cramping, pain, gas, bloating, diarrhea, and constipation.

These factors are known as triggers and include a variety of foods and ingredients. Smoking, hormones, and stress can also act as IBS triggers. Triggers vary from person to person.

Many people with IBS manage their condition by cutting certain foods out of their diet, though it may take some trial and error to find out which foods are problems for your system.

Stress and hormones may not be as easily avoided as certain food triggers of IBS, but that doesn’t mean you can’t do anything about them. You may be able to limit your symptoms through stress management techniques and by taking steps to avoid other triggers during times of hormonal change, according to leading academic medical centers.

The Foods That Tend to Trigger Irritable Bowel Syndrome

Exactly how certain foods lead to symptoms of IBS isn’t completely understood. It’s unlikely for a true food allergy to be the cause of IBS symptoms. But other forms of intolerance may apply to a range of foods and ingredients, according to Mayo Clinic.


Leading hospitals and the National Institutes of Health say common dietary triggers of IBS include these items:

While it’s not a specific food trigger, a low-fiber diet can also make you more likely to experience IBS symptoms.

This means that to maintain healthy digestion, it’s important to focus not just on avoiding foods but on including the right foods in your diet, too. Just be careful to go slow when adding fiber to your diet, as too much too soon can cause gas and bloating. The National Institute of Diabetes and Digestive and Kidney Diseases suggests adding 2 to 3 grams (of soluble fiber) per day to prevent gas and bloating.

Staying well-hydrated by drinking three to four pint glasses of water each day can help you avoid symptoms.

It’s important to keep track of what you eat to try to figure out how your diet may be affecting your IBS symptoms.

You may need to stick to a dietary change for several weeks before you notice a change in your symptoms.

Even once you think you have your triggers figured out, it’s possible you’ll need to start tracking your diet again if you experience a change in the frequency or severity of your symptoms.

If you’re having trouble coming up with a diet that works for you on your own, talking with a dietitian or nutritionist can help.

How Hormonal Shifts Are Related to Symptoms of IBS

Women are twice as likely to develop IBS as men, which indicates that hormones may play a role in the condition, according to the Mayo Clinic.

In fact, many women notice that their IBS symptoms are worse during or around the time of their menstrual periods.
Taking estrogen for hormone replacement therapy, before or after menopause, is also a known risk factor for IBS and may prolong the condition later into life than it usually persists.

According to an an article published in March 2021 in the Journal of Neurogastroenterology and Motility, sex hormones like estrogen may influence a variety of functions related to digestion, including gut motility (digestive action), the barrier function of the intestine, and activation of the immune system in the intestinal lining.

Previous research noted that sex hormones may also explain differences in the stress response between men and women.

This suggests that an interactive effect between hormonal changes and external or psychological stressors may worsen IBS symptoms in some people.

Different IBS symptoms often occur with different hormonal changes, according to the article.

Pregnancy often causes the following changes, which are related to high levels of estrogen and progesterone:

  • Reduced pain sensitivity, including digestive pain
  • Worsening of constipation

Menopause often causes the following changes, which are related to a drop in female sex hormones:

  • Reduced overall IBS symptoms
  • Increased incidence of constipation

In women, taking oral contraceptives sometimes reduces IBS symptoms during or around menopause.

Hormonal differences may explain why diarrhea is more common in men with IBS than in women, as reported in a review article. Some studies of both younger and middle-aged men have shown that they are more likely to report diarrheal symptoms compared with women, and it may be related to their sex hormones and proteins in the blood that transport these hormones.

The Links Between Stress and Irritable Bowel Syndrome

Many people with IBS experience a worsening of symptoms during times of psychological stress.

Stress doesn’t appear to directly cause symptoms, according to a Mayo Clinic patient website, yet it may make them more severe or frequent.

Some reviews have argued more strongly that psychological stress does impact the brain and gut in ways that may be a key factor in progression to IBS.

People with certain mental health issues or who have had traumatic experiences are also more likely to develop IBS, including the following:

  • Anxiety
  • Depression
  • History of sexual, physical, or emotional-spiritual abuse
These ties to IBS indicate that a variety of psychological factors may be related to intestinal function. Researchers are still trying to understand what's involved in this connection, but recent research has even found a link between childhood trauma and gut function, according to a study published in August 2019 in Brain, Behavior, and Immunity.

IBS may also cause psychological distress that contributes to anxiety or depression. The potential for a two-way relationship between psychological factors and intestinal symptoms poses a challenge to researchers.

According to an article published in November 2021 in the journal Brain Sciences noted that psychological stress can manifest as “somatization” (known as medically unexplained symptoms) in patients with IBS and is associated with specific features seen in their brain on MRI.

Other research published as a review and summary of prior research noted that both acute (sudden) and chronic (long term) stress can affect intestinal function during early life and adulthood.

The review further notes that Intestinal changes affected by stress include gut motility (digestive action), secretion of enzymes and juices, and the intestine’s barrier function.

The makeup of healthy and unhealthy bacteria in the digestive tract may also be affected.

Additional reporting by Jordan M. Davidson.

Editorial Sources and Fact-Checking

  1. Irritable Bowel Syndrome. Mayo Clinic. March 17, 2018.
  2. Irritable Bowel Syndrome (IBS): Living With. Cleveland Clinic. January 20, 2015.
  3. 5 Foods to Avoid If You Have IBS. Johns Hopkins Medicine.
  4. Best and Worst Foods for IBS. Cleveland Clinic. February 18, 2014.
  5. Eating, Diet, and Nutrition for Irritable Bowel Syndrome. National Institute of Diabetes and Digestive and Kidney Diseases. November 2017.
  6. Mulak A, Taché Y, Larauche M. Sex Hormones in the Modulation of Irritable Bowel Syndrome. World Journal of Gastroenterology. March 14, 2014.
  7. Qin HY, Cheng CW, Tang XD, Bian ZX. Impact of Psychological Stress on Irritable Bowel Syndrome. World Journal of Gastroenterology. October 21, 2014.
  8. Rincel M, Aubert P, Chevalier J, et al. Multi-Hit Early Life Adversity Affects Gut Microbiota, Brain and Behavior in a Sex-Dependent Manner. Brain, Behavior, and Immunity. August 2019.
  9. Cecilia Grinsvall C, Van Oudenhove L, Dupont P, et al. Altered Structural Covariance of Insula, Cerebellum and Prefrontal Cortex Is Associated with Somatic Symptom Levels in Irritable Bowel Syndrome (IBS). Brain Sciences. November 29, 2021.
  10. Kichul Yoon K, Kim N. Roles of Sex Hormones and Gender in the Gut Microbiota. Journal of Neurogastroenterology and Motility. March 2021.
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