A 70 year old male presents to your office with a 3 month history of slowly worsening epigastric pain, nausea, and fatigue. His medical and surgical history are otherwise unremarkable. On careful questioning he also relates a 15 pound weight loss over the last 3 months and early satiety over the last month. Physical exam reveals a thin male in no acute distress with epigastric tenderness and no clear mass. Rectal exam is positive for blood. Labs reveal a microcytic anemia.