Researchers conducted a study with 28 people with irritable bowel syndrome (IBS) to investigate whether gluten worsens symptoms. Participants were asked to eat a gluten-free diet for three weeks, then randomly assigned to consume cereal bars containing wheat, gluten without wheat components, or neither. The results showed no significant difference in symptom severity between the groups, casting doubt on the role of gluten as a common trigger for IBS symptoms.
Source: https://www.newscientist.com/article/2489039-gluten-may-not-actually-trigger-many-irritable-bowel-syndrome-cases