In this study patients diagnosed using Rome IV criteria with irritable bowel syndrome with constipation are included. The study was approved by the Ethic Committee of the University of Medicine and Pharmacy "Gr. T Popa" Iasi to be conducted at the Institute of Gastroenterology and Hepatology of Clinical Emergency Hospital "Sf. Spiridon" Iasi. The patients are assigned after a randomized scheme to one of the groups: diet restriction scheme or diet restriction scheme plus a product with inuline, choline and silymarin. After 28 days the patients are crossed between the groups and followed for additional 28 days diet scheme with or without inuline, choline and silymarin supplementation. All the patients are evaluated initially, in the day 28 and in the day 57 for the stool habits, stool characteristics using Brystol Scale and symptoms severity (abdominal pain, frequency of abdominal pain, bloating severity, patients satisfaction in relation with stool frequency and the impact of IBS on daily activity) as appreciated by the patients for the last 10 days.