A new study reveals that while most dietitians work one-on-one with patients to reintroduce FODMAP foods, the lack of a standard approach may make this critical step in IBS care more variable than expected.
Research: Reintroducing fermentable oligosaccharides, disaccharides, monosaccharides, and polyols into clinical practice: exploring gaps and opportunities. Image credit: Alkema Natalia / Shutterstock
Recent research published in journals Progress of gastric hep highlights a notable discrepancy among registered dietitians (RDs) during the food reintroduction phase of a low-fermentable oligosaccharide, disaccharide, monosaccharide, polyol (FODMAP) diet.
Although most clinicians provide individualized counseling and follow-up, approaches vary in timing, sequencing, and response management, reflecting the lack of standardized protocols.
For patients with irritable bowel syndrome (IBS), this variation can create uncertainty at critical stages of treatment, making it difficult to pinpoint trigger foods, prolonging the reintroduction process, or leading to excessive dietary restriction, ultimately impacting treatment outcomes and quality of life.
Background on IBS management and low FODMAPs
IBS refers to a condition in which the interaction between the gut and the brain is dysregulated. Patients often experience repeated abdominal discomfort and changes in bowel habits, significantly impacting productivity, health care utilization, and overall health.
A low FODMAP diet is an evidence-based strategy for managing IBS and is increasingly considered a first-line treatment. However, despite its three-stage structure, research has mainly focused on the restriction stage, and the reintroduction stage, which is essential for identifying individual triggers and guiding long-term dietary individualization, is relatively underexplored.
This critical step remains variably performed in clinical practice, as treatment recommendations are limited and inconsistent.
Addressing these gaps through clearer protocols and better clinical insights is essential to standardize care while maintaining appropriate individualization, enhancing decision-making, and ultimately supporting more consistent patient care.
Design of a dietitian survey for FODMAP reintroduction
In this national cross-sectional study, researchers conducted an online survey to examine RD practice patterns during food reintroduction among individuals on a low-FODMAP diet. They recruited RDs through professional networks, social media, and listservs.
The study involved dietitians working in a variety of settings. These include academic and hospital-based roles, private and ambulatory care, telemedicine, retail, campus-based primary care settings, and geriatric care.
The team worked with two gastroenterologists and four RDs to create a 16-question survey. This study used Likert scales with multiple-choice questions to explore important aspects of clinical practice. These include approaches such as starting a low-FODMAP diet (LFD), implementing a FODMAP challenge, educating patients, and providing follow-up care.
Researchers also assessed starting and progression doses, challenge volume, number of foods tested for each FODMAP subtype, and duration and sequence of food reintroduction.
The researchers used descriptive statistical methods to summarize responses and present categorical data as percentages. They also conducted a comparative analysis to assess the variation in LFD performance across different clinical settings.
Variations in low FODMAP reintroduction practices
Survey responses revealed that clinical practice during the reintroduction phase varied even among responding dietitians, highlighting real differences in the care provided to patients.
Of the 145 RDs who responded to the survey, half (50%) practiced in a private setting and 26% worked in an academic or university setting. Most RDs (63%) reported trying one food per FODMAP group during reintroduction.
About 37% tested more than one food. In most cases (73%), dietitians involved patients in deciding the order of reintroduction, highlighting the emphasis on shared decision-making in real-world care.
If symptoms did not occur, 80% of RD increased FODMAP doses within 3 days, generally suggesting an aggressive progression strategy. However, when symptoms appeared, clinicians were more likely to provide individualized care. More than 62% of them adjusted the waiting period based on the individual’s severity, while others followed a fixed schedule.
Almost all respondents (98%) conducted reintroductions through one-on-one consultations, highlighting the individualized nature of this stage, with 63% completing the process within two months.
Differences also emerged between practice environments. Dietitians at academic and university centers tend to schedule fewer visits during the reintroduction phase, and follow-up after completion is more common.
They also often relied on standardized starting dose protocols and were more likely to complete a given reintroduction challenge in a shorter time frame. In contrast, those in non-academic settings appear to adopt a more flexible approach, perhaps reflecting differences in resources and patient needs.
Overall, our findings revealed that there is considerable heterogeneity in dosing strategies and their implementation, which may contribute to differences in patient experience and clinical outcomes. More than 70% of RDs used a standardized starting dose and escalated to once-daily doses.
Other researchers have used fixed or alternative dosing approaches and highlighted the variability in implementation of the reintroduction phase in everyday real-world practice. At the same time, the study also identified several areas of consistency, such as frequent use of handouts and post-reintroduction follow-up.
Standardization of FODMAP reintroduction protocols
This study revealed that significant improvements need to be made during the reintroduction phase of the low FODMAP diet. Although dietitians widely provide individualized care and ongoing support, important aspects such as dosage, timing, and sequence are not applied consistently, potentially impacting patient outcomes, interpretation of symptoms, and duration of the entire process.
Looking forward, it will be important to develop standardized evidence-based protocols and strengthen expert consensus to reduce unwarranted variation while maintaining individualized care. This study also highlights important research gaps, particularly the lack of comparative data regarding reintroduction strategies.
Future studies should focus on optimizing the challenge protocol and evaluating its impact on clinical outcomes. In parallel, targeted education and training for dietitians can help align practice across settings and ultimately improve the effectiveness and patient experience of FODMAP-based dietary management.
The results of this study are based on self-reported survey responses and the sample may not be completely representative of all dietitians who practice a low FODMAP diet, so the results should be interpreted with these limitations in mind.
Reference magazines:
- Pelletier, K., Villarreal, M., Klar, R., et al. (2026). Reintroducing fermentable oligosaccharides, disaccharides, monosaccharides, and polyols into clinical practice: A survey of gaps and opportunities, Gastro Hep Advances;5, DOI: 10.1016/j.gastha.2026.100908, https://www.ghadvances.org/article/S2772-5723(26)00029-4/fulltext
