Figure 1

Anatomy of ileal pouch anal anastomosis (IPAA). Patients who undergo a two-stage IPAA procedure initially undergo a total colectomy with the construction of the ileal pouch, which is anastomosed to the rectum. Diversion of the fecal stream occurs through an ileostomy. Study subjects were initially sampled at this stage (visit 1) with specimens harvested from the diverted pouch. In the second stage of the IPAA procedure, the diverting ileostomy is taken down and continuity is restored to the ileum, restoring the flow of intestinal contents to the ileal pouch. The subsequent samples were obtained from the ileal pouch, which was accessed via the rectum (visits 2, 3 and 4). Control samples were obtained from healthy individuals who had the same anatomy as the IPAA subjects prior to the first stage of the procedure.