Inclusion Criteria:  Patients over 18 years old Diagnosis of irritable bowel syndrome according to the ROME IV classification Negative blood test: determination of IgE; anti-transglutaminase IgA assay (celiac disease) Symptoms potentially related to a food allergy Sufficient cooperation and understanding to comply with the requirements of the study with a post-Cellvizio medical examination at 2 weeks, 2 months and 6 months  Exclusion Criteria:  Patients under 18 Patient benefiting from a legal protection measure (curatorship, guardianship, etc.) Pregnant or breastfeeding woman Known allergy to fluorescein Digestive cancer (stomach cancer colon rectal cancer)