Introduction There are many similarities between inflammatory bowel disease (IBD) and allergic diseases, including similar epidemiological data, pathomechanism, clinical course and even treatment methods. So far, many studies of IBD comorbidity with other diseases, including allergy, but mainly in adults, have been conducted. Aim To analyse the prevalence of allergic diseases, i.e. food allergy (FA), cow’s milk allergy (CMA), atopic dermatitis (AD), allergic rhinitis (AR) and asthma in children with IBD. Material and methods The study included 105 IBD patients from the Department of Paediatrics, Allergology and Gastroenterology of Collegium Medicum in Bydgoszcz and 100 children without IBD from the Outpatient Clinics. The authors applied the validated questionnaire as a study method. Results At least one allergic disease was found in 26 (43%) IBD children. The allergological diagnosis was made in IBD children more frequently than in the control group ( p = 0.04). The difference was more noticeable with regards to skin prick tests ( p = 0.02). FA was the most common disease; it was noted in 19 (32%) IBD children; followed by: AD – in 13 (22%), CMA – in 12 (20%), AR – in 10 (17%) and asthma – in 6 (10%) children. The prevalence of allergic diseases in the control and study groups was comparable ( p > 0.05). There was no correlation between age of IBD children and allergy ( p > 0.05). Asthma was significantly more common in children undergoing biological treatment ( p = 0.01). Conclusions Children with IBD should be constantly monitored by medical professionals, not only due to the underlying disease but also due to a possible concomitant allergic disease.

Currently, the only treatment for coeliac disease (CD) is a strict, lifelong gluten-free diet (GFD); however, their completeness with regard to energy and macro- and micronutrients remains poorly understood. Paediatric studies are often limited by a low quality and a lack of controls, and their findings should be interpreted with caution. The aim of the present study was to evaluate nutritional imbalances in children with CD on a strict GFD. Methods: A single-centre prospective cohort study was conducted. A total of 48 children with CD (33 girls, mean age 11.8 ± 3.68 years) on a strict GFD (mean duration 5.02 ± 3.87 years) were compared with 50 non-coeliac subjects (26 girls, mean age 10.2 ± 3.97 years). In both groups, anthropometric measurements (body height, weight and BMI) and laboratory tests (haemoglobin level, calcium and magnesium serum concentration, folic acid, vitamin B1, B2, B6 and B12 level) were checked. Additionally, in coeliac subjects, a 3-day food record for energy and macro- and micronutrient intake assessment were determined, and the values were compared to those in non-CD participants and the dietary reference intake (DRI) standards. Results: The CD children were more likely to demonstrate significantly lower serum vitamin B1 and folic acid levels compared to controls (p = 0.01 and p = 0.002, respectively). Although mean serum calcium values were within normal ranges, they were significantly lower in CD subjects than controls (p = 0.01). Mean calcium, folic acid and vitamin D intake was below the dietary recommendations in the CD group (69.9%, 71.2% and 68.9% DRI, respectively) but did not differ significantly between CD and non-coeliac subjects. In turn, the mean supply of proteins and carbohydrates in the CD group substantially exceeded the recommended levels (190.3% and 189.4% DRI, respectively) but was similar to controls. A significantly higher number of CD children were classified as underweight, and a significantly lower number as overweight or obese, compared with controls (p < 0.001). Conclusion: Although children with CD receive nutritional education at diagnosis, a GFD often does not provide a balanced set of macro- and micronutrients. This is mainly due to unhealthy dietary habits, as commonly observed in the general population. Children with CD should be informed that while their diet should be free of gluten, it should nevertheless cover all their nutrition requirements in the long term.