Usually slowly. Polyps generally grow slowly, taking years to get big enough to be visible. However, there do seem to be some that are faster growing and more aggressive. I have certainly seen them show up in less than a year after a previous colonoscopy.
Variable. Generally we discuss polyp growth as being exponential, so that from a single cell to a polyp 1 cubic centimeter in size probably takes 2-3 years. Hyoweveer due the exponential growth they can double in size in shorter times. Some polyp types may be faster growing than others.
Abnormal gowths . Neoplasia is a general term to describe abnormal growth pattern, cancer-like, unregulated by normal bodily control systems. Some colon polyps are destined to become cancerous, some are not, so all polyps are usually removed when they are found so we can distinguish the difference under the microscope, not by appearance which can fool you. Read more...