Colorectal cancer is the second most common cause of cancer-related death in the U.S. Although removal of pre-malignant polyps has been shown to reduce the risk of colorectal cancer, up to 50% of removed colonic polyps are hyperplastic with no malignant potential. Removal of these benign polyps exposes the patient to polypectomy-related complications and cost without any benefit. Current standard endoscopes with the use of accessory confocal endomicroscopy probe will allow both routine and confocal microscopy imaging. Colonoscopies or upper endoscopies will be performed as routine including conscious sedation. A special fiber through the scope, combined with a small amount of dye called fluorescein given by vein, will be used to obtain microscopic views during the endoscopic procedure. If a colorectal lesion or other GI lesion is found that would normally require biopsy, the site of biopsy will be evaluated by confocal imaging with the Cellvizio-GI Fiberoptic probes prior to biopsy or removal of the suspicious tissue. Following image acquisition, the lesion will be biopsied or removed as per standard clinical care. Standard endoscopic variables for each lesion will be recorded including: name and record number, date, time, an exact time of fluorescein injection and time of image acquisition, lesion location, size, and suspected findings (inflammation, dysplasia, type of polyp) and final histological diagnosis.