Colon polyps range in diameter from less than a quarter of an inch to several inches, according to the American Society for Gastrointestinal Endoscopy. Polyps can be flat or mushroom-shaped and can occur in several places in the gastrointestinal tract.
Most colon polyps are small and do not cause symptoms, explains WebMD. If polyps do grow to a large size, symptoms such as diarrhea, constipation or rectal bleeding may occur. Some colon polyps can develop into colon cancer, which is why the Mayo Clinic recommends regular screening tests, such as colonoscopies, which detect polyps at the early stage when they are easiest to remove.