Inclusion Criteria:

• IBS defined by Rome IV criteria
• Non IBS-C
• Moderate to severe symptoms defined by IBS-SSS≥175
• Able to safely undergo and consent to colonoscopy

Exclusion Criteria

• Immune deficiency or treatment with immunosuppressive medications
• Severe bowel or medical disease precluding administration of bowel prep
• Severe bowel or medical disease precluding colonoscopy with conscious sedation
• Active cancer
• Pregnant or lactating
• Abdominal surgery (exception of splenectomy, partial hepatectomy, partial/unilateral nephrectomy, laparoscopy, pelvic floor repair, mesh, liposuction, fundoplication, tubal ligation, gastric sleeve, oophorectomy, hernia, appendectomy, cholecystectomy, caesarean section and hysterectomy)
• Severe psychiatric disorder (HADS-A or D>16), or diagnosed alcohol or drug abuse disorder
• New probiotics or treatment with antibiotics, NSAIDs (within 4 wks prior to study entry)
• Use of treatments known to affect colonic motility (with exception of loperamide)
• Diagnosed h/o bleeding disorder
• Organic GI diseases (IBD, celiac disease, microscopic colitis)
• Chronic kidney or liver disease
• Absolute neutrophil count (ANC) <500 IU/ml