The purpose of this study is to study development of dysplasia in the ileal mucosa among patients with Ulcerative Colitis and who previous have hade risk factors for developing cellular changes/dysplasia, i.e. previous dysplasia and/or carcinoma in their specimen.

Objective Some of the rare complications reported in patients with an ileal pouch-anal anastomosis (IPAA) after colectomy for chronic ulcerative colitis are dysplasia and carcinoma. The supposed pathway is for the ileal pouch mucosa to go through adaptational changes then to progress through the phases of chronic pouchitis, dysplasia and subsequently to adenocarcinoma. The purpose of this study is to study development of dysplasia in the ileal mucosa among patients with Ulcerative Colitis and who previous have hade risk factors for developing cellular changes/dysplasia, i.e. previous dysplasia and/or carcinoma in their specimen.

Methods In a cohort of 680 patients having IPAA with a median follow-up time of 18 years, 75 patients with risk factors for dysplasia were identified. Sixty-five patients were eligible for inclusion, fifty-six patients accepted to participate in the study. Patients are invited for clinical examination, endoscopy with macroscopic evaluation as well as mucosal biopsies. The biopsies are reviewed and evaluated by two independent pathologists, experienced in colonic pathology, concerning morphological changes, dysplasia and potential carcinoma Results Architectural structural changes, inflammation and reactive atypia is noted in the rectal cuff and ileal pouch. So far, none of the biopsies showed genuine dysplasia after a follow up for 18 years (Range 12-23 years). In this respect there is full agreement between the two pathologists.

Further microscopic evaluation are planned for the rest of the participating patients.

Inclusion Criteria:

• UC (Ulcerative Colitis)
• IPAA
• risk factor for dysplasia

Exclusion Criteria:

• Not able to give consent
• CD (Crohns disease)