Administration of a Molecular Complex of Resins, Polysaccharides and Polyphenols in Irritable Bowel Syndrome.

Inclusion Criteria: * 1\. Male or female patients aged 18 to 75 years (inclusive); * 2\. Diagnosis of IBS according to ROME IV criteria (Appendix 3); * 3\. Abdominal pain score ≥ 4 on a 11-point NRS, on at least 2 days of the 14 days prior to the baseline visit and on at least 2 days of the last 14 days of the washout period, and pain score not \> 8 in more than 7 days of each of the two above-mentioned periods; * 4\. Signed Informed Consent; * 5\. Patients' ability to comply with the study procedures; * 6\. Stable diet in the two months prior to the screening visit; * 7\. \*Negative colonoscopy, defined as the absence of clinically relevant changes or of changes nonetheless relevant in relation to study participation risk, performed during the run-in period, unless: * a colonoscopy was performed within the previous 5 years and was negative as intended above, or, if more than one was performed within the previous 5 years, the last being negative as intended above; * the symptoms, if any, for which the last colonoscopy was performed, have remained unchanged; * 8\. Postmenopausal female patients, i.e., females who have not had a menstrual period for at least 12 months or women who have undergone surgical sterilisation (tubal ligation or ovary removal). If not, women of childbearing potential must follow reliable contraceptive treatment. * Inclusion criteria applicable only for patients \> 50 years of age Exclusion Criteria: * 1\. Patients taking treatments that may significantly affect the efficacy outcomes measures, such as: probiotics and prebiotics (unless contained in milk-derived foods such as yogurt and cheese); drugs with adsorbent/sequestrant properties such as diosmectite; 5-HT3 receptor antagonist drugs, e.g. ondasetron; drugs that modify gastro-intestinal motility, e.g. "final" anti-cholinergic agents such as loperamide, or cholinergic agents; laxatives and faecal softeners) unless they have been taken at a stable dose for at least four weeks prior to the screening visit. * 2\. Patients taking tricyclic antidepressants within six months prior to the screening visit; * 3\. Patients taking opioid-containing analgesics within one month prior to the screening visit; * 4\. Patients taking antibiotics within one month prior to the screening visit; * 5\. Patients with relevant organic, systemic or metabolic disease, or laboratory changes, that are deemed significant based on specific ranges of normality; * 6\. Patients with organic bowel diseases; * 7\. Patients with unstable psychiatric conditions; * 8\. Patients who have undergone major abdominal surgery, except appendectomy; * 9\. Known hypersensitivity to one or more of the components of the products. * 10.Women with known or planned pregnancy or breastfeeding; * 11.Patients with malignancies of any type, or with a history of prior malignancies, except for patients with a history of extra-intestinal malignancies that have been surgically removed and have not relapsed within the five years prior to participation.