Ask the doctor: Do I need to take precautions if I stop taking warfarin before a colonoscopy?

Q. I am due to have a colonoscopy. My cardiologist told me that I will need to stop taking Coumadin, which I take for atrial fibrillation, a few days before the procedure and get some injections. Is that really necessary?

A. Warfarin (Coumadin, Jantoven, generic) is an important medication for people with atrial fibrillation because it helps prevent stroke-causing blood clots from forming inside the heart. The concern with colonoscopy is that the doctor might need to take a biopsy or remove a polyp during the procedure, and being on warfarin increases the risk of bleeding.