This study is being done to:

To attempt to increase the detection of precancerous colon tissue in patients with chronic ulcerative colitis and primary sclerosing cholangitis;

To determine if an investigational scope that can look at the lining of the colon in different ways will help the doctor identify abnormal tissue in patients with chronic ulcerative colitis and concurrent primary sclerosing cholangitis; and

To determine if this investigational scope can accurately detect precancerous or cancerous tissue in patients with chronic ulcerative colitis that are known to have had cancerous or precancerous tissue in the past.

Patients with concurrent chronic ulcerative colitis and primary sclerosing cholangitis or patients with chronic ulcerative colitis and known colorectal dysplasia or cancer, presenting for surveillance colonoscopy will be recruited. After giving informed consent patients will then undergo colonoscopy in a segmental fashion. Colonoscopy with white light will be performed to the cecum and examination will be performed on withdrawal. First conventional white light will be used to examine the cecum and ascending colon and random biopsies will be obtained. All endoscopically apparent lesions will be biopsied separately. Immediately following will be examination of that segment of cecum and ascending colon under AFI first, then NBI with targeted biopsies of suspicious areas being taken. The AFI and NBI modality will be achieved by simply flipping a switch.. If necessary, washing of oozing blood from random biopsy sites will be performed., The remainder of the colon will be assessed in like fashion: transverse, descending and rectosigmoid. Because high definition endoscopy is the default modality, this will be in use throughout the procedure.

All lesions detected will be documented and biopsied for a maximum of four biopsies per suspicious lesion. Note will be taken of which modality resulted in visualization of the lesion. Data on the factors under study will be collected: i) disease type (CUC + PSC or CUC with known dysplasia), ii) Age, iii) Sex, iv) length of time with disease, v) extent of disease, vi) the interaction between iv and v will be collected. In addition, dysplasia yes/no will be established after biopsy histology is established and the modality under which abnormalities were observed will also be recorded.

Inclusion Criteria:

• patients requiring a clinically indicated surveillance colonoscopy
• able to give informed written consent
• history of chronic ulcerative colitis and colonic dysplasia/or cancer or primary sclerosing cholangitis

Exclusion Criteria:

• patients with known colonic obstruction
• INR ./= 2.5 or thrombocytopenia ,50,000
• patients with clinically important cardiopulmonary disease who are unable to safely undergo prolonged conscious sedation
• pregnancy
• symptomatic coronary artery disease

Patients presenting with chronic ulcerative colitis and Primary sclerosing cholangitis and/or patients with chronic ulcerative colitis and known colorectal dysplasia or cancer needing a surveillance colonoscopy.