The medical management of inflammatory bowel disease (IBD) has evolved over the years thanks to the newly available therapies and the biochemical and endoscopic monitoring of the disease. Several in-remission IBD patients still complain of gastrointestinal symptoms, suggesting a possible overlap between IBD and Disorders of Gut-Brain-Interaction (DGBIs), classified and diagnosed according to the Rome IV criteria, with a worldwide prevalence of about 40% in the general population. In adult patients with in-remission IBD, the prevalence of any DGBI has been reported to reach up to 41%, resulting in significantly higher rates in Crohn's disease (CD) than in ulcerative colitis (UC). Regarding the pediatric population, according to a meta-analysis conducted in 2015, the worldwide prevalence of functional abdominal pain disorders (FAPDs), a subtype of DGBIs including functional dyspepsia, irritable bowel syndrome (IBS), abdominal migraine, and functional abdominal pain not otherwise specified (FAP-NOS), in children is about 13.5%, with IBS reported as the most frequent disorder (8.8%). Only a few studies were conducted on pediatric patients to investigate the association between IBD and DGBIs. A meta-analysis conducted in 2022 reported an overall prevalence of FAPDs ranging between 9.6% and 29.5% in children with in-remission IBD, with the overall prevalence of IBS in these patients ranging between 3.9% and 16.1%. Therefore, despite the differences in criteria used to define quiescent IBD in the included studies, an increased overall prevalence of IBS and FAPDs in children with IBD was described. Nevertheless, none used the current Rome IV criteria to diagnose DGBIs, and only the prevalence of IBS and FAPDs was analyzed. The primary aim of our study was to assess the prevalence of commonly reported DGBIs (Functional nausea and vomiting disorders, Functional abdominal pain disorders, Functional defecation disorders) in pediatric patients with quiescent IBD, compared to a control group of healthy children. Secondly, we aimed to investigate the presence of any other factors associated with the presence of DGBIs in our population, regardless of the IBD status.

Inclusion Criteria:

In-remission IBD patients:

• Clinical remission was defined as PUCAI/aPCDAI < 10
• biochemical remission was defined as CRP < 0.5 mg/ml and faecal calprotectin < 100 microg/g
• Endoscopic remission defined as CDEIS < 6 for CD and Mayo score ≤ 1 for UC.

Exclusion Criteria:

• diabetes (type I and II)
• thyroid disease
• major abdominal surgery in the previous two years
• connective tissue disease
• ongoing corticosteroid or antibiotic therapy.

Pediatric patients with quiescent IBD recruited during their routine control visit at the Outpatients Pediatric Gastrointestinal Unit of three Italian referral centres in Rome, Italy (Fondazione Policlinico Universitario A. Gemelli IRCCS, Sapienza University of Rome - Sant'Andrea University Hospital, Bambino Gesù Children Hospital).