Inflammatory bowel diseases (IBD) may influence eating habits and lead some patients to adopt restrictive dietary behaviours to control gastrointestinal symptoms. In some cases, these behaviours may become maladaptive and resemble eating disorders, including avoidant/restrictive food intake disorder (ARFID).

This observational cross-sectional study assesses the prevalence of eating disorder risk and ARFID risk among adult patients with IBD. Participants complete validated questionnaires evaluating eating behaviours, nutritional status, and IBD-related disability. Clinical and demographic data are also collected.

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic relapsing conditions characterized by persistent inflammatory activity, unpredictable disease course, and recurrent gastrointestinal symptoms. These factors may substantially influence patients' dietary habits. Many patients with IBD modify or restrict their diet in an attempt to prevent symptom exacerbation or disease flares. Although dietary restriction may represent an adaptive behaviour during active disease, it may persist over time and become maladaptive.

Restrictive eating behaviours in IBD may overlap with eating disorders, including avoidant/restrictive food intake disorder (ARFID). ARFID is characterized by restrictive food intake that is not primarily driven by body image concerns, but rather by mechanisms such as fear of adverse gastrointestinal consequences, low appetite or reduced interest in eating, and avoidance of specific foods. In patients with IBD, these behaviours may contribute to nutritional impairment, psychological distress, and disability.

This observational cross-sectional study assesses the prevalence of eating disorder risk and ARFID risk among adult patients with a confirmed diagnosis of IBD. Consecutive eligible patients are enrolled during routine outpatient visits. Demographic and clinical data are collected at enrolment, including disease type, age at diagnosis, disease duration, disease phenotype, previous treatments, previous surgery, extraintestinal manifestations, current therapy, laboratory markers, and disease activity.

Eating disorder risk is assessed using the Eating Attitudes Test-26 (EAT-26). ARFID risk is evaluated using the Nine-Item Avoidant/Restrictive Food Intake Disorder Screen (NIAS-9), including its subdomains related to picky eating, low appetite or limited interest in eating, and fear of adverse consequences. Nutritional status is assessed using the Patient-Generated Subjective Global Assessment (PG-SGA). IBD-related disability is evaluated using the IBD-Disk and a modified IBD-Disk including a diet-related item.

Clinical disease activity is assessed using validated disease-specific indices, including the partial Mayo score for ulcerative colitis and the Harvey-Bradshaw Index for Crohn's disease. Endoscopic activity, when available, is evaluated using the Mayo Endoscopic Subscore for ulcerative colitis and the Simple Endoscopic Score for Crohn's Disease for Crohn's disease. The study also evaluates associations between altered eating behaviours, disease activity, malnutrition risk, dietary impairment, and IBD-related disability.

The study aims to improve the identification of patients with IBD who are at risk of maladaptive restrictive eating behaviours and who may benefit from structured nutritional or psychological assessment as part of routine IBD care. The uploaded study describes the same core design elements: adult IBD patients enrolled during routine outpatient visits, ARFID risk assessed with NIAS-9, eating disorder risk with EAT-26, nutritional status with PG-SGA, and disability with IBD-Disk/mDISK. 

Inclusion Criteria:

• Adult patients aged 18 years or older.
• Confirmed diagnosis of inflammatory bowel disease, including Crohn's disease or ulcerative colitis.
• Patients evaluated during routine outpatient IBD visits.
• Ability to understand and complete the study questionnaires.

Exclusion Criteria:

• Previous diagnosis or known history of eating disorders.
• Severe unmanaged psychiatric conditions.
• Pregnancy.
• Inability to complete the questionnaires or provide reliable study information.

Adult patients with a confirmed diagnosis of inflammatory bowel disease, including Crohn's disease or ulcerative colitis, enrolled during routine outpatient visits at participating IBD centres. Participants complete validated questionnaires assessing eating behaviours, nutritional status, and IBD-related disability, with concurrent collection of clinical and demographic data.

Individual participant data will not be shared because the dataset includes sensitive clinical and questionnaire-based information. Aggregate results will be shared through publications and scientific presentations.