Inclusion Criteria:  All patients will be selected according to Rome IV criteria for the diagnosis of IBS, which include:  Recurrent abdominal pain at least 1 day/week in the last 3 months, with two or more of the following criteria:  Related to defecation Associated with a change in frequency of stool Associated with a change in form of stool. Criteria achieved for the last 3 months with symptom onset at least 6 months before diagnosis  Exclusion Criteria:  • Rectal bleeding  Anemia Weight loss Onset after 50 years of age Recent antibiotic use Abnormal abdominal examination (organomegaly, lump) Family history of colorectal cancer. Family history of inflammatory bowel disease, or celiac disease.