Up to 15% of patients with ulcerative colitis (UC) will require surgery, the most common of which is the total proctocolectomy (TPC) with ileal pouch-anal anastomosis (IPAA). Since 1980, the ‘J’ pouch has revolutionized the lives of thousands of patients, providing restoration of intestinal continuity and avoidance of a permanent end ileostomy. Unfortunately, pouchitis is common after surgery with cumulative incidence rates of 50% at two years. Patients with pouchitis experience increased bowel movement frequency, urgency, pelvic pain, rectal bleeding and/or incontinence – symptoms that are reminiscent of their disease before surgery. Antibiotics are the mainstay of acute pouchitis treatment, however approximately 20% of patients develop chronic pouchitis and require long-term antibiotic therapy or immunosuppressive therapy. The risk of surgical pouch removal and transition to a permanent end ileostomy is 5-10% in patients with chronic pouchitis. Fecal microbiota transplantation (FMT) has been successfully used in the treatment of recurrent Clostridiodes difficile infection and has shown benefit in the treatment of UC in clinical trials. The success of FMT in these patients is because of the reconstitution of the recipient’s unhealthy microbiome with the donor’s healthy microbiome. A number of studies have evaluated FMT in patients with chronic pouchitis, but have proven unsuccessful. This is likely because these studies have used stool from patients with a colon and transplanted it into patients with a pouch. This is problematic because the microbiome of the colon and pouch are not similar, and putting healthy stool from a colon may not reconstitute a healthy pouch microbiome. The specific purpose of this project is to transplant stool from patients with a healthy pouch to patients with an inflamed pouch. We hypothesize that the stool from patients with a healthy pouch is well suited to reconstitute the microbiome of patients with an inflamed pouch.