We propose a randomized controlled study to determine the detection rates of neoplasia with high definition colonoscopy alone, high definition dye spraying chromoendoscopy or High definition iSCAN virtual chromoendoscopy in patients with long standing colitis (8 years from diagnosis except primary sclerosing cholangitis when surveillance starts at diagnosis) CD or UC.

We hypothesized that these novel endoscopic techniques using High definition colonoscopy with virtual chromoendoscopy -iScan 2 and 3 may be superior to high definition colonoscopy alone and similar to using dye spraying chromoendoscopy for detection of dysplasia and neoplasia in patients with long standing IBD.

We will aim to demonstrate if we can avoid dye spraying during the procedure and save expense and considerable time.

In addition, we can hope to produce evidence and inform the way in which we perform surveillance colonoscopy especially without large number of multiple random biopsies but only few targeted" smart and intelligent" biopsies using high definition colonoscopy with iSCAN technique as is already the European practice in several centres.

Inclusion Criteria:

Clinical and histological diagnosis of UC or colonic CD-extensive or pancolitis.

UC -CD Disease duration 8 years from diagnosis UC-CD with associated primary sclerosing cholangitis from diagnosis Ulcerative Colitis Activity Index Mayo score 0-1 (inactive disease) Crohn's disease Activity Index - Harvey Bradshaw score <4 (dysplasia detection requires quiescent inflammatory bowel disease)

Exclusion Criteria:

Known intraepithelial neoplasia or colorectal cancer or other neoplasia Coagulopathy which may prevent biopsies Pregnancy Inability to obtain informed consent

Inflammatory bowel disease patients undergoing surveillance colonoscopy