Serial Gut Microbiome and Bacterial Gene Markers Changes After Endoscopic Resection of Colorectal Advanced Neoplasia

This study is tracking changes in gut bacteria (the microbiome) and related gene markers before and after an endoscopic procedure to remove precancerous growths or early-stage cancer from the colon or rectum, to understand how the gut microbiome relates to colorectal disease. **You may be eligible if...** - You are between 18 and 90 years old - You need an endoscopic procedure (such as EMR or ESD) to remove a large polyp or early-stage colorectal cancer - You have given written informed consent **You may NOT be eligible if...** - You have a condition that makes colonoscopy unsafe (e.g., bowel obstruction or perforation) - You have active gastrointestinal bleeding or are on blood thinners that cannot be paused - You are pregnant or breastfeeding - You have severe health problems (ASA Grade 4 or above) Talk to your doctor to see if this trial is right for you.