Colon cancer is a lethal disease that starts many years before the actual cancer appears. We are developing new treatments to prevent colon cancer. In order to prove whether a treatment that prevents colon cancer works or not, it is necessary to study thousands of high risk individuals for many years. Such a strategy is costly and does not permit rapid testing of the many promising drugs, nutrients, and lifestyle changes that might help prevent colon cancer. We hypothesize that over a 1 month's time interval, a drug will alter important chemicals and genes in cells that are critical to the development of colon cancer. We propose to test this hypothesis by obtaining a small biopsy of polyps that are found in a patient's colon. Instead of removing the polyp, we will test whether or not a potential cancer preventive drug inhibits these chemicals or genes. We will randomize (flip a coin) and treat these individuals with either aspirin, an aspirin like drug that inhibits function of a key enzyme involved in cancer development, or a placebo for twenty-eight days. Once the treatment is complete, we will remove the remaining polyp and accompanying normal tissue. We will assess whether the drug treatment changed important genes or chemicals in the polyp and normal tissue and compare the difference treatments. If we succeed, we will be able to assessment many potential treatments that might prevent colon cancer and select those that are best for further assessment in larger, more expensive clinical trials.