Individuals who underwent ileal pouch–anal anastomosis following colectomy were recruited at Mount Sinai Hospital in Toronto, Ontario, Canada, in compliance with the hospital’s research ethics board. The cohort consisted of subjects with a diagnosis of ulcerative colitis or familial adenomatous polyposis, which are disorders that primarily affect the large intestine. The subjects were recruited at least 1 year after closure of their ileostomy. An extensive panel of clinical information and biospecimens were collected on recruitment, including a clinical disease activity index, physician’s global assessment, complete history of medication use, endoscopic and histopathologic evaluation of the prepouch ileum, complete blood cell count, C-reactive protein level, whole blood for DNA extraction, and tissue biopsy specimens for RNA analysis. Where necessary, these data were collected in a format compatible with both the Heidelberg Pouchitis Activity Score and Pouchitis Disease Activity Index to assess inflammatory state.25,26
