Functional Abdominal Pain Disorders and Constipation in Children on Gluten-Free Diet

Background & Aims: We studied the prevalence of functional abdominal pain disorders (FAPDs) and functional constipation (FC) in a large prospective cohort of children with celiac disease on a strict gluten-free diet (GFD). Methods: We performed a prospective cohort study, from 2016 through 2018, in a tertiary care center in Italy, of 417 patients (37% male; mean age, 13.7 y) with a diagnosis of celiac disease (European Society for Paediatric Gastroenterology Hepatology, and Nutrition criteria) who had been on a strict GFD for more than 1 year and had negative results from serologic tests after being on the GFD. Parents and children (>10 y) were asked to fill in a questionnaire on pediatric gastrointestinal symptoms, according to Rome IV criteria. Patients’ closest siblings (or cousins) who had negative results from serologic test for celiac disease were used as controls (n = 373; 39% male; mean age, 13.5 y). Results: We found a higher prevalence of FAPDs among patients with celiac disease (11.5%) than controls (6.7%) (P < .05); the relative risk (RR) was 1.8 (95% CI, 1.1–3.0). Irritable bowel syndrome (IBS) and FC defined by the Rome IV criteria were more prevalent in patients with celiac disease (7.2% for IBS and 19.9% for FC) than controls (3.2% for IBS and 10.5% for FC) (P < .05 and P < .001, respectively); the RR for IBS was 2.3 (95% CI, 1.1–4.6) and the RR for functional constipation was 2.1 (95% CI, 1.4–3.2). We found no differences in the prevalence of other subtypes of FAPDs. A logistic regression showed that younger age (P < .05) and a higher level of anti–transglutaminase IgA at diagnosis (P < .04) were associated with FAPDs (in particular for IBS) irrespective of GFD duration. Conclusions: Celiac disease is associated with an increased risk of IBS and FC. Strategies are needed to manage IBS and FC in patients with celiac disease.