Gastrointestinal Polyp

In this study, the investigators are studying new ways to look for abnormal tissues of the gastrointestinal tract during an endoscopy. We are using a VEGF-A targeting fluorescent probe and a NIR-II fluorescent endoscope to help detect abnormal tissues that are hard to see by the naked eye. The main purposes of this study include: 1. To translate the NIR-II approach into the endoscopy, and understand its advantages and limitations on detecting abnormal tissues in gastrointestinal. 2. To validate whether topical administration of a targeting probe can stick to abnormal tissues and be detected by the NIR-II endoscope. 3. To validate the safety and effectiveness of the topical administration of VEGF-A targeting probes for clinical application.