To assess the adherence to gluten free diet by measuring faecal and urinary gluten immunogenic peptides (GIP). This will provide an objective measure for adherence.

The adherence to the GFD can be assessed through a dietary interview performed by a registered dietitian or patient self-reports, mucosal healing, assessed by a small bowel biopsy or CD serological screening tests showing decreasing levels of antibodies. However, none of these methods offer an accurate measure of dietary compliance. A novel method to monitor the adherence to the GFD by detection of immune-dominant gluten peptides in human faeces or urine using the anti-α -gliadin G12 antibody was described recently in the literature. Gluten peptides, in particular peptides equivalent to the immunogenic - α -gliadin-33-mer peptide, are resistant to gastrointestinal digestion and that ensures a significant amount of the ingested gluten is excreted in faeces. Consequently, recovery of detectable amounts of the immunogenic fraction in faeces or urine indicates that gluten has passed through the digestive tract, and in the case of urine was absorbed, and, therefore, that gluten has been consumed .

Inclusion Criteria:

• Age 2-17 years.
• Either diagnosis of celiac disease or, in controls, no systemic disease or inflammation
• For all groups parents will provide informed consent.

Exclusion Criteria:

° Children with suspected or known inflammatory bowel disease or other gastrointestinal or systemic diseases.

1. Children and adolescents aged 2-17 years, reported to be on gluten free diet for at least a year, diagnosed with celiac disease
2. Children and adolescents aged 2-17 years that are reported to be noncompliant with gluten free diet, diagnosed with celiac disease for at least 1 year.
3. Healthy controls aged 2-17 years old matched for age and sex.