Normal iron studies (i.e. ferritin, total iron, TIBC, percent saturation) in an anemic patient CANNOT be used to rule out CANCER causing a bleed. IRON STUDIES can be falsely normal and trick you into thinking that the patient is not iron deficient (from a bleed), when in fact he really is! YOU STILL NEED TO LOOK FOR (or at the very least consider) cancer causing blood loss from every anemic adult patient!
For example, check a UA to rule out hematurea caused from renal cell carcinoma or bladder cancer.
Order a colonoscopy (or possibly a set of 3 stool guiacs) when appropriate.
Do a work-up for abnormal vaginal bleeding when clinically warranted.