Fecal microbiota transplantation (FMT) is a strategy that infuses a fecal suspension containing a healthy donor's microbiota into a patient's gut to restore his/her intestinal microbiome. FMT has a higher cure rate than standard antibiotic treatment for recurrent Clostridium difficile infections,and shows promising results in Inflammatory bowel disease（IBD）.However, few studies have evaluated whether FMT is effective to treat Irritable bowel syndrome(IBS).The investigators propose to determine the efficiency and safety of FMT in patients with Irritable bowel syndrome.