Two IBS Diets Studied: Improvement Does Not Prove Equivalence

What the researchers in Turkey examined

The study, published in BMC Gastroenterology, involved 72 adults with irritable bowel syndrome, ages 18 to 64. They were randomly assigned to two sequences: a low-FODMAP diet followed by a lactose-free and gluten-free diet, or the reverse order. Each stage lasted four weeks, with a week of returning to their usual diet in between.

This was an intervention trial, not simply a comparison of people who chose different diets themselves. However, it involved one medical center and a short follow-up. The data were collected in 2020 and 2021; October 2026 is the article's publication date, not when participants received treatment.

What was found, and what remains open

According to the original paper, digestive symptom scores and anxiety and depression scores declined over time in both sequences. The difference between sequences at the end was not statistically significant. The researchers emphasize that the trial was not designed to demonstrate equivalence.

Limitations include self-reporting, a lack of systematic documentation of IBS subtypes, and the possibility that effects from the first stage carried over into the second. The trial was also registered retrospectively. The result therefore encourages further investigation but does not establish which approach is preferable for a particular patient.

When reading a result like this, it is important to separate two questions: whether participants improved, and whether the comparison allows a winner to be chosen. A positive answer to the first does not guarantee an answer to the second. A measure of psychological distress is also not equivalent to a medical diagnosis or proof that a diet treats depression.

What a low-FODMAP diet means

FODMAP refers to groups of carbohydrates that may trigger symptoms in some people with IBS. It is not another word for gluten, which is a protein, nor an instruction to give up all carbohydrates. Lactose is milk sugar; sensitivity to it is a different question from a response to the protein in grains.

According to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, NIDDK, different adjustments may help different people. A low-FODMAP diet is tried for a limited period, after which foods can be reintroduced gradually according to professional guidance and individual response. The goal is not to build a permanent list of forbidden foods from a news headline.

Fiber is not a single uniform category either: the institute notes that soluble fiber may help with IBS symptoms, while adding fiber too quickly can increase gas. More on these differences appears in the article on fiber and IBS.

Before removing milk or bread from your diet

A practical implication for readers in Israel is to arrive at a consultation with a specific question: what you want to test, how to track symptoms, and when to reassess the diet. These are more useful questions than deciding to eliminate several food groups at once. When everything changes together, it is also harder afterward to describe which change accompanied relief.

NIDDK notes that a diary of food, drinks, and symptoms can help a doctor or dietitian identify patterns. Such a record is a tool for discussion, not a test that diagnoses a sensitivity on its own. It can also include a day without difficulties, so the discussion does not focus only on the last meal before pain began.

For readers particularly uncertain about grains, the article on gluten without celiac disease offers further background. A trial in IBS should not automatically lead to treatment conclusions for Crohn's disease, colitis, or another condition.

What this news changes today

The study raises a relevant clinical question: does the order in which dietary approaches are tried change the outcome? It does not offer a universal formula, and certainly does not instruct anyone to replace existing treatment. For someone who has already found a tolerable diet with a professional, publication of the comparison alone is no reason to start again.

According to NIDDK, evaluating IBS relies on symptoms, medical history, and sometimes tests to rule out other conditions. Dietary adjustments are part of that process. The new finding is worth taking to an appointment as an additional question, alongside what is already known about your body and personal routine.

This is general news information and is not a substitute for personal advice from a doctor or dietitian.