Inclusion Criteria:  IBS patients: Both sexes with a diagnosis of irritable bowel syndrome variety diarrhea according to the Rome IV criteria  Healthy Controls: Relatives of patients who do not show any disease, who do not take medication or present symptoms.  Exclusion Criteria:  patients with digestive tract disease, systemic diseases such as severe heart, kidney or liver failure, history of previously known digestive tract surgeries and / or intestinal adhesions, diabetes mellitus, cirrhosis, inflammatory bowel disease, celiac disease, patients with cognitive impairment, alcoholics, lack of consent . patients who have received antibiotics in the last month.