This study focuses on patients with early rectal cancer, specifically examining suspicious growths in the rectum that may contain cancer cells or abnormal cell changes. The study uses a special medication called SGM-101, which is a fluorescent substance that can help doctors better see the difference between normal tissue and potentially cancerous areas during examination procedures.

The medication SGM-101 is given through an intravenous infusion (delivered directly into a vein). This substance is designed to attach to specific markers that are typically found on cancer cells, making them visible under special lighting during examination. The purpose of the study is to determine if this fluorescent imaging technique can effectively distinguish between normal tissue and areas with different levels of cell abnormalities in the rectum.

The study is conducted in two phases. The first phase aims to find the most effective dose of the medication. The second phase tests how well the fluorescent imaging technique works in identifying different types of tissue changes. During the procedure, doctors use a special camera system that can detect the fluorescent signals from the medication, allowing them to examine the suspicious areas in detail.