At the start of the study, you will be asked questions about your medical history, have a complete physical exam, and have around 2 tablespoons of blood drawn for blood tests as part of your routine care for familial adenomatous polyposis. Also, blood tests such as fasting blood glucose and lipid profiling (cholesterol, LDL, HDL and triglyceride) will be assessed to determine eligibility. Women who are able to have children must have a negative blood pregnancy test within 14 days of starting celecoxib.