 The purpose of this study is to assess how effective celecoxib is in limiting production of a hormone, prostaglandin, in the subjects body. It is felt that this hormone is involved in the evolution of pre-cancerous growths in the colon to cancerous stage or in the progression of an existing cancer. To answer this question, some subjects are given the new investigational drug, and other subjects a placebo. A placebo is a capsule that contains inactive ingredients. Only by comparing the response of two subject groups, one receiving placebo inactive, and one receiving celecoxib active, will we be able to know whether or not celecoxib actually works. The outcome we are assessing is the hormone activity before and after celecoxib is given. 