Researchers surveyed over 5,000 young Italian adults to understand how many people with irritable bowel syndrome (IBS) also have trouble with gluten. They found that about 1 in 3 IBS patients reported symptoms when eating gluten, even though they don’t have celiac disease. These patients also reported feeling more tired, foggy-headed, and experiencing mood issues. Interestingly, most of these people stuck with a gluten-free diet because it helped them feel better. This research suggests that doctors might want to ask IBS patients about gluten sensitivity, as avoiding gluten could be a helpful treatment option for some people.

The Quick Take

  • What they studied: Whether people with irritable bowel syndrome (IBS) also experience problems when eating gluten, even if they don’t have celiac disease
  • Who participated: 5,108 young adults living in 13 different Italian cities who answered an online survey about their digestive health and diet
  • Key finding: About 29% of people with IBS also reported gluten sensitivity symptoms, compared to only 9% of people without IBS. This difference was very clear and unlikely to be due to chance (P<0.0001)
  • What it means for you: If you have IBS, there’s a decent chance you might feel better by trying a gluten-free diet. However, this was based on what people reported about themselves, not medical testing, so talk to your doctor before making major diet changes

The Research Details

Researchers created a survey and asked over 5,000 people in Italian cities to fill it out between January and March 2022. The survey asked about their digestive symptoms, whether they had been diagnosed with IBS, whether they experienced problems with gluten, and whether they followed a gluten-free diet. They sorted people into groups: those with IBS and those without, and within the IBS group, those who also reported gluten problems and those who didn’t.

The researchers used standard medical criteria (called Rome IV) to identify who truly had IBS based on their symptoms. They then compared the different groups to see if people with both IBS and gluten sensitivity had different experiences than people with just IBS.

This approach is useful because it captures real-world experiences from a large number of people. By surveying many people across different cities, the researchers could see patterns that might help doctors understand how common this combination of problems is. Understanding that IBS and gluten sensitivity often occur together could help doctors offer better treatment options to their patients.

This study is based on what people reported about themselves rather than medical tests, which means some answers might not be completely accurate. The researchers did use a validated questionnaire, which means the survey questions were tested and proven to be reliable. The large sample size (over 5,000 people) makes the findings more trustworthy. However, because this was a one-time survey rather than following people over time, we can’t be completely sure about cause-and-effect relationships.

What the Results Show

Out of 5,108 people surveyed, 819 people (16%) met the medical criteria for IBS. Of those 819 people with IBS, 238 people (29%) also reported experiencing gluten sensitivity symptoms. This means that nearly 3 out of every 10 IBS patients in this study also had gluten-related symptoms.

When comparing people with IBS to people without IBS, the difference was striking: 29% of IBS patients reported gluten sensitivity compared to only 9% of people without IBS. This large difference was statistically significant, meaning it’s very unlikely to have happened by chance.

People who had both IBS and gluten sensitivity reported more overall health problems beyond just digestive issues. They more frequently experienced fatigue (extreme tiredness), brain fog (difficulty thinking clearly), and a general sense of not feeling well. They also reported more neuropsychiatric issues, meaning problems with mood and mental health.

An important finding was about diet choices: 61% of people with both IBS and gluten sensitivity were following a gluten-free diet, compared to only 41% of people with IBS alone. This suggests that people who experience both conditions are more likely to stick with avoiding gluten, possibly because they notice it helps them feel better.

Previous research has shown that IBS and gluten sensitivity can have overlapping symptoms, making them difficult to tell apart. This study confirms that these two conditions do frequently occur together in the same people. The finding that about 29% of IBS patients also report gluten sensitivity is higher than what some previous studies suggested, which may reflect differences in how people were selected or surveyed.

This study relied entirely on what people reported about themselves rather than medical testing for celiac disease or wheat allergy. Some people might have thought they had gluten sensitivity when they actually didn’t, or vice versa. The survey was only conducted in Italy with young adults, so the results might not apply to older people or people from other countries with different diets. Additionally, because this was a one-time survey, we can’t determine whether gluten sensitivity causes IBS symptoms or if having IBS makes people more likely to develop gluten sensitivity.

The Bottom Line

If you have IBS, it may be worth discussing with your doctor whether trying a gluten-free diet could help your symptoms. The evidence suggests this could be beneficial for some people, particularly if you also experience fatigue, brain fog, or mood issues. However, don’t eliminate gluten without medical guidance, as you’ll want to ensure you’re still getting proper nutrition. Consider asking your doctor about testing for celiac disease first, since that’s a more serious condition that requires different management. Confidence level: Moderate—this research suggests a possible benefit, but more rigorous testing would strengthen the evidence.

This research is most relevant for people who have been diagnosed with IBS and are looking for additional treatment options. It’s also important for doctors who treat IBS patients, as it suggests they should ask about gluten sensitivity. People with celiac disease or wheat allergies should follow their doctor’s advice rather than relying on this research. If you have severe digestive symptoms, you should see a doctor for proper diagnosis before making diet changes.

If gluten sensitivity is contributing to your IBS symptoms, you might notice improvements within 2-4 weeks of avoiding gluten, though some people take longer. However, improvement isn’t guaranteed, and some people with IBS won’t feel better by avoiding gluten. It’s worth giving it a fair trial (at least 4 weeks) while working with your doctor or a dietitian to ensure you’re eating a balanced diet.

Want to Apply This Research?

  • Track daily symptoms on a scale of 1-10 (digestive discomfort, fatigue, brain fog, mood) and note what you ate that day. After 2-4 weeks, compare your symptom scores on days when you avoided gluten versus days when you consumed gluten to see if there’s a pattern.
  • If you decide to try reducing gluten, start by eliminating obvious sources (bread, pasta, cereals) for one week while tracking how you feel. Then gradually reintroduce gluten-containing foods one at a time to identify which ones, if any, trigger your symptoms.
  • Use the app to maintain a 4-week symptom and food diary. Create a simple chart showing your top 3 symptoms and rate them daily. At the end of each week, review whether gluten-containing days correlate with worse symptoms. Share this data with your doctor to make informed decisions about your diet.

This research describes what people reported about their own experiences and is not a substitute for professional medical diagnosis or treatment. Do not eliminate gluten from your diet without consulting your doctor first, as this could mask celiac disease or other serious conditions that require specific medical management. If you have severe or persistent digestive symptoms, seek medical evaluation. Always work with a healthcare provider or registered dietitian before making significant dietary changes, especially if you have IBS or suspect gluten sensitivity. This study does not prove that gluten causes IBS symptoms in all people—individual responses vary greatly.